item.h 60.3 KB
Newer Older
1
/* Copyright (C) 2000-2003 MySQL AB & MySQL Finland AB & TCX DataKonsult AB
unknown's avatar
unknown committed
2

unknown's avatar
unknown committed
3 4 5 6
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.
unknown's avatar
unknown committed
7

unknown's avatar
unknown committed
8 9 10 11
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
unknown's avatar
unknown committed
12

unknown's avatar
unknown committed
13 14 15 16 17
   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */


18
#ifdef USE_PRAGMA_INTERFACE
unknown's avatar
unknown committed
19 20 21
#pragma interface			/* gcc class implementation */
#endif

22
class Protocol;
unknown's avatar
unknown committed
23
struct st_table_list;
unknown's avatar
unknown committed
24
void item_init(void);			/* Init item functions */
25
class Item_field;
unknown's avatar
unknown committed
26

27 28 29

/*
   "Declared Type Collation"
unknown's avatar
unknown committed
30
   A combination of collation and its derivation.
31 32 33 34
*/

enum Derivation
{
35 36 37
  DERIVATION_IGNORABLE= 5,
  DERIVATION_COERCIBLE= 4,
  DERIVATION_SYSCONST= 3,
38 39 40 41 42
  DERIVATION_IMPLICIT= 2,
  DERIVATION_NONE= 1,
  DERIVATION_EXPLICIT= 0
};

43 44
/*
  Flags for collation aggregation modes:
unknown's avatar
unknown committed
45 46 47 48
  MY_COLL_ALLOW_SUPERSET_CONV  - allow conversion to a superset
  MY_COLL_ALLOW_COERCIBLE_CONV - allow conversion of a coercible value
                                 (i.e. constant).
  MY_COLL_ALLOW_CONV           - allow any kind of conversion
unknown's avatar
unknown committed
49
                                 (combination of the above two)
unknown's avatar
unknown committed
50 51 52 53
  MY_COLL_DISALLOW_NONE        - don't allow return DERIVATION_NONE
                                 (e.g. when aggregating for comparison)
  MY_COLL_CMP_CONV             - combination of MY_COLL_ALLOW_CONV
                                 and MY_COLL_DISALLOW_NONE
54 55 56 57
*/

#define MY_COLL_ALLOW_SUPERSET_CONV   1
#define MY_COLL_ALLOW_COERCIBLE_CONV  2
unknown's avatar
unknown committed
58 59 60
#define MY_COLL_ALLOW_CONV            3
#define MY_COLL_DISALLOW_NONE         4
#define MY_COLL_CMP_CONV              7
61

62 63 64 65 66 67 68 69 70 71 72 73 74 75 76
class DTCollation {
public:
  CHARSET_INFO     *collation;
  enum Derivation derivation;
  
  DTCollation()
  {
    collation= &my_charset_bin;
    derivation= DERIVATION_NONE;
  }
  DTCollation(CHARSET_INFO *collation_arg, Derivation derivation_arg)
  {
    collation= collation_arg;
    derivation= derivation_arg;
  }
77
  void set(DTCollation &dt)
78
  { 
79 80
    collation= dt.collation;
    derivation= dt.derivation;
81 82 83 84 85 86 87 88 89 90
  }
  void set(CHARSET_INFO *collation_arg, Derivation derivation_arg)
  {
    collation= collation_arg;
    derivation= derivation_arg;
  }
  void set(CHARSET_INFO *collation_arg)
  { collation= collation_arg; }
  void set(Derivation derivation_arg)
  { derivation= derivation_arg; }
91 92 93
  bool aggregate(DTCollation &dt, uint flags= 0);
  bool set(DTCollation &dt1, DTCollation &dt2, uint flags= 0)
  { set(dt1); return aggregate(dt2, flags); }
94 95 96 97
  const char *derivation_name() const
  {
    switch(derivation)
    {
98
      case DERIVATION_IGNORABLE: return "IGNORABLE";
99 100
      case DERIVATION_COERCIBLE: return "COERCIBLE";
      case DERIVATION_IMPLICIT:  return "IMPLICIT";
101
      case DERIVATION_SYSCONST:  return "SYSCONST";
102 103 104 105 106 107 108
      case DERIVATION_EXPLICIT:  return "EXPLICIT";
      case DERIVATION_NONE:      return "NONE";
      default: return "UNKNOWN";
    }
  }
};

109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222

/*************************************************************************/
/*
  A framework to easily handle different return types for hybrid items
  (hybrid item is an item whose operand can be of any type, e.g. integer,
  real, decimal).
*/

struct Hybrid_type_traits;

struct Hybrid_type
{
  longlong integer;

  double real;
  /*
    Use two decimal buffers interchangeably to speed up += operation
    which has no native support in decimal library.
    Hybrid_type+= arg is implemented as dec_buf[1]= dec_buf[0] + arg.
    The third decimal is used as a handy temporary storage.
  */
  my_decimal dec_buf[3];
  int used_dec_buf_no;

  /*
    Traits moved to a separate class to
      a) be able to easily change object traits in runtime
      b) they work as a differentiator for the union above
  */
  const Hybrid_type_traits *traits;

  Hybrid_type() {}
  /* XXX: add traits->copy() when needed */
  Hybrid_type(const Hybrid_type &rhs) :traits(rhs.traits) {}
};


/* Hybryd_type_traits interface + default implementation for REAL_RESULT */

struct Hybrid_type_traits
{
  virtual Item_result type() const { return REAL_RESULT; }

  virtual void
  fix_length_and_dec(Item *item, Item *arg) const;

  /* Hybrid_type operations. */
  virtual void set_zero(Hybrid_type *val) const { val->real= 0.0; }
  virtual void add(Hybrid_type *val, Field *f) const
  { val->real+= f->val_real(); }
  virtual void div(Hybrid_type *val, ulonglong u) const
  { val->real/= ulonglong2double(u); }

  virtual longlong val_int(Hybrid_type *val, bool unsigned_flag) const
  { return (longlong) val->real; }
  virtual double val_real(Hybrid_type *val) const { return val->real; }
  virtual my_decimal *val_decimal(Hybrid_type *val, my_decimal *buf) const;
  virtual String *val_str(Hybrid_type *val, String *buf, uint8 decimals) const;
  static const Hybrid_type_traits *instance();
};


struct Hybrid_type_traits_decimal: public Hybrid_type_traits
{
  virtual Item_result type() const { return DECIMAL_RESULT; }

  virtual void
  fix_length_and_dec(Item *arg, Item *item) const;

  /* Hybrid_type operations. */
  virtual void set_zero(Hybrid_type *val) const;
  virtual void add(Hybrid_type *val, Field *f) const;
  virtual void div(Hybrid_type *val, ulonglong u) const;

  virtual longlong val_int(Hybrid_type *val, bool unsigned_flag) const;
  virtual double val_real(Hybrid_type *val) const;
  virtual my_decimal *val_decimal(Hybrid_type *val, my_decimal *buf) const
  { return &val->dec_buf[val->used_dec_buf_no]; }
  virtual String *val_str(Hybrid_type *val, String *buf, uint8 decimals) const;
  static const Hybrid_type_traits_decimal *instance();
};


struct Hybrid_type_traits_integer: public Hybrid_type_traits
{
  virtual Item_result type() const { return INT_RESULT; }

  virtual void
  fix_length_and_dec(Item *arg, Item *item) const;

  /* Hybrid_type operations. */
  virtual void set_zero(Hybrid_type *val) const
  { val->integer= 0; }
  virtual void add(Hybrid_type *val, Field *f) const
  { val->integer+= f->val_int(); }
  virtual void div(Hybrid_type *val, ulonglong u) const
  { val->integer/= (longlong) u; }

  virtual longlong val_int(Hybrid_type *val, bool unsigned_flag) const
  { return val->integer; }
  virtual double val_real(Hybrid_type *val) const
  { return (double) val->integer; }
  virtual my_decimal *val_decimal(Hybrid_type *val, my_decimal *buf) const
  {
    int2my_decimal(E_DEC_FATAL_ERROR, val->integer, 0, &val->dec_buf[2]);
    return &val->dec_buf[2];
  }
  virtual String *val_str(Hybrid_type *val, String *buf, uint8 decimals) const
  { buf->set(val->integer, &my_charset_bin); return buf;}
  static const Hybrid_type_traits_integer *instance();
};

/*************************************************************************/

unknown's avatar
unknown committed
223
typedef bool (Item::*Item_processor)(byte *arg);
unknown's avatar
unknown committed
224
typedef Item* (Item::*Item_transformer) (byte *arg);
unknown's avatar
unknown committed
225

226
typedef void (*Cond_traverser) (const Item *item, void *arg);
227

unknown's avatar
unknown committed
228
class Item {
unknown's avatar
unknown committed
229
  Item(const Item &);			/* Prevent use of these */
unknown's avatar
unknown committed
230 231
  void operator=(Item &);
public:
232
  static void *operator new(size_t size) {return (void*) sql_alloc((uint) size); }
233
  static void *operator new(size_t size, MEM_ROOT *mem_root)
234
  { return (void*) alloc_root(mem_root, (uint) size); }
235
  /* Special for SP local variable assignment - reusing slots */
236
  static void *operator new(size_t size, Item *reuse, uint *rsize);
unknown's avatar
unknown committed
237
  static void operator delete(void *ptr,size_t size) { TRASH(ptr, size); }
238
  static void operator delete(void *ptr, MEM_ROOT *mem_root) {}
unknown's avatar
unknown committed
239

240
  enum Type {FIELD_ITEM= 0, FUNC_ITEM, SUM_FUNC_ITEM, STRING_ITEM,
241
	     INT_ITEM, REAL_ITEM, NULL_ITEM, VARBIN_ITEM,
unknown's avatar
SCRUM  
unknown committed
242
	     COPY_STR_ITEM, FIELD_AVG_ITEM, DEFAULT_VALUE_ITEM,
unknown's avatar
unknown committed
243 244
	     PROC_ITEM,COND_ITEM, REF_ITEM, FIELD_STD_ITEM,
	     FIELD_VARIANCE_ITEM, INSERT_VALUE_ITEM,
245
             SUBSELECT_ITEM, ROW_ITEM, CACHE_ITEM, TYPE_HOLDER,
unknown's avatar
unknown committed
246
             PARAM_ITEM, TRIGGER_FIELD_ITEM, DECIMAL_ITEM};
unknown's avatar
SCRUM  
unknown committed
247

unknown's avatar
unknown committed
248
  enum cond_result { COND_UNDEF,COND_OK,COND_TRUE,COND_FALSE };
249 250

  enum traverse_order { POSTFIX, PREFIX };
251
  
252 253 254
  /* Reuse size, only used by SP local variable assignment, otherwize 0 */
  uint rsize;

unknown's avatar
unknown committed
255 256 257 258 259
  /*
    str_values's main purpose is to be used to cache the value in
    save_in_field
  */
  String str_value;
unknown's avatar
unknown committed
260
  my_string name;			/* Name from select */
261 262
  /* Original item name (if it was renamed)*/
  my_string orig_name;
unknown's avatar
unknown committed
263 264
  Item *next;
  uint32 max_length;
265
  uint name_length;                     /* Length of name */
unknown's avatar
unknown committed
266
  uint8 marker, decimals;
unknown's avatar
unknown committed
267 268
  my_bool maybe_null;			/* If item may be null */
  my_bool null_value;			/* if item is null */
269
  my_bool unsigned_flag;
unknown's avatar
unknown committed
270
  my_bool with_sum_func;
271
  my_bool fixed;                        /* If item fixed with fix_fields */
272
  DTCollation collation;
273

unknown's avatar
unknown committed
274 275
  // alloc & destruct is done as start of select using sql_alloc
  Item();
276
  /*
unknown's avatar
unknown committed
277
     Constructor used by Item_field, Item_ref & aggregate (sum) functions.
278 279
     Used for duplicating lists in processing queries with temporary
     tables
280
     Also it used for Item_cond_and/Item_cond_or for creating
unknown's avatar
unknown committed
281
     top AND/OR structure of WHERE clause to protect it of
282
     optimisation changes in prepared statements
283
  */
284
  Item(THD *thd, Item *item);
unknown's avatar
unknown committed
285 286
  virtual ~Item()
  {
unknown's avatar
unknown committed
287
#ifdef EXTRA_DEBUG
unknown's avatar
unknown committed
288
    name=0;
unknown's avatar
unknown committed
289
#endif
unknown's avatar
unknown committed
290
  }		/*lint -e1509 */
unknown's avatar
unknown committed
291
  void set_name(const char *str,uint length, CHARSET_INFO *cs);
292
  void rename(char *new_name);
unknown's avatar
unknown committed
293
  void init_make_field(Send_field *tmp_field,enum enum_field_types type);
294
  virtual void cleanup();
295
  virtual void make_field(Send_field *field);
296
  Field *make_string_field(TABLE *table);
unknown's avatar
unknown committed
297
  virtual bool fix_fields(THD *, struct st_table_list *, Item **);
unknown's avatar
unknown committed
298
  /*
unknown's avatar
unknown committed
299
    should be used in case where we are sure that we do not need
unknown's avatar
unknown committed
300 301 302
    complete fix_fields() procedure.
  */
  inline void quick_fix_field() { fixed= 1; }
unknown's avatar
unknown committed
303
  /* Function returns 1 on overflow and -1 on fatal errors */
304
  int save_in_field_no_warnings(Field *field, bool no_conversions);
unknown's avatar
unknown committed
305
  virtual int save_in_field(Field *field, bool no_conversions);
unknown's avatar
unknown committed
306
  virtual void save_org_in_field(Field *field)
307
  { (void) save_in_field(field, 1); }
unknown's avatar
unknown committed
308
  virtual int save_safe_in_field(Field *field)
309
  { return save_in_field(field, 1); }
310
  virtual bool send(Protocol *protocol, String *str);
311
  virtual bool eq(const Item *, bool binary_cmp) const;
312 313
  virtual Item_result result_type() const { return REAL_RESULT; }
  virtual Item_result cast_to_int_type() const { return result_type(); }
314
  virtual enum_field_types field_type() const;
unknown's avatar
unknown committed
315
  virtual enum Type type() const =0;
316
  /* valXXX methods must return NULL or 0 or 0.0 if null_value is set. */
unknown's avatar
unknown committed
317 318 319 320 321 322 323 324 325 326
  /*
    Return double precision floating point representation of item.

    SYNOPSIS
      val_real()

    RETURN
      In case of NULL value return 0.0 and set null_value flag to TRUE.
      If value is not null null_value flag will be reset to FALSE.
  */
327
  virtual double val_real()=0;
unknown's avatar
unknown committed
328 329 330 331 332 333 334 335 336 337
  /*
    Return integer representation of item.

    SYNOPSIS
      val_int()

    RETURN
      In case of NULL value return 0 and set null_value flag to TRUE.
      If value is not null null_value flag will be reset to FALSE.
  */
unknown's avatar
unknown committed
338
  virtual longlong val_int()=0;
339 340 341 342 343
  /*
    This is just a shortcut to avoid the cast. You should still use
    unsigned_flag to check the sign of the item.
  */
  inline ulonglong val_uint() { return (ulonglong) val_int(); }
344 345 346
  /*
    Return string representation of this item object.

unknown's avatar
unknown committed
347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403
    SYNOPSIS
      val_str()
      str   an allocated buffer this or any nested Item object can use to
            store return value of this method.

    NOTE
      Buffer passed via argument  should only be used if the item itself
      doesn't have an own String buffer. In case when the item maintains
      it's own string buffer, it's preferable to return it instead to
      minimize number of mallocs/memcpys.
      The caller of this method can modify returned string, but only in case
      when it was allocated on heap, (is_alloced() is true).  This allows
      the caller to efficiently use a buffer allocated by a child without
      having to allocate a buffer of it's own. The buffer, given to
      val_str() as argument, belongs to the caller and is later used by the
      caller at it's own choosing.
      A few implications from the above:
      - unless you return a string object which only points to your buffer
        but doesn't manages it you should be ready that it will be
        modified.
      - even for not allocated strings (is_alloced() == false) the caller
        can change charset (see Item_func_{typecast/binary}. XXX: is this
        a bug?
      - still you should try to minimize data copying and return internal
        object whenever possible.

    RETURN
      In case of NULL value return 0 (NULL pointer) and set null_value flag
      to TRUE.
      If value is not null null_value flag will be reset to FALSE.
  */
  virtual String *val_str(String *str)=0;
  /*
    Return decimal representation of item with fixed point.

    SYNOPSIS
      val_decimal()
      decimal_buffer  buffer which can be used by Item for returning value
                      (but can be not)

    NOTE
      Returned value should not be changed if it is not the same which was
      passed via argument.

    RETURN
      Return pointer on my_decimal (it can be other then passed via argument)
        if value is not NULL (null_value flag will be reset to FALSE).
      In case of NULL value it return 0 pointer and set null_value flag
        to TRUE.
  */
  virtual my_decimal *val_decimal(my_decimal *decimal_buffer)= 0;
  /*
    Return boolean value of item.

    RETURN
      FALSE value is false or NULL
      TRUE value is true (not equal to 0)
404
  */
unknown's avatar
unknown committed
405
  virtual bool val_bool();
406 407 408 409 410 411 412 413 414 415
  /* Helper functions, see item_sum.cc */
  String *val_string_from_real(String *str);
  String *val_string_from_int(String *str);
  String *val_string_from_decimal(String *str);
  my_decimal *val_decimal_from_real(my_decimal *decimal_value);
  my_decimal *val_decimal_from_int(my_decimal *decimal_value);
  my_decimal *val_decimal_from_string(my_decimal *decimal_value);
  longlong val_int_from_decimal();
  double val_real_from_decimal();

416
  virtual Field *get_tmp_table_field() { return 0; }
417
  virtual Field *tmp_table_field(TABLE *t_arg) { return 0; }
unknown's avatar
unknown committed
418
  virtual const char *full_name() const { return name ? name : "???"; }
unknown's avatar
unknown committed
419 420 421 422 423 424 425

  /*
    *result* family of methods is analog of *val* family (see above) but
    return value of result_field of item if it is present. If Item have not
    result field, it return val(). This methods set null_value flag in same
    way as *val* methods do it.
  */
426
  virtual double  val_result() { return val_real(); }
unknown's avatar
unknown committed
427 428
  virtual longlong val_int_result() { return val_int(); }
  virtual String *str_result(String* tmp) { return val_str(tmp); }
unknown's avatar
unknown committed
429 430 431 432
  virtual my_decimal *val_decimal_result(my_decimal *val)
  { return val_decimal(val); }
  virtual bool val_bool_result() { return val_bool(); }

433
  /* bit map of tables used by item */
unknown's avatar
unknown committed
434
  virtual table_map used_tables() const { return (table_map) 0L; }
435 436 437 438 439 440 441 442 443 444 445 446 447 448
  /*
    Return table map of tables that can't be NULL tables (tables that are
    used in a context where if they would contain a NULL row generated
    by a LEFT or RIGHT join, the item would not be true).
    This expression is used on WHERE item to determinate if a LEFT JOIN can be
    converted to a normal join.
    Generally this function should return used_tables() if the function
    would return null if any of the arguments are null
    As this is only used in the beginning of optimization, the value don't
    have to be updated in update_used_tables()
  */
  virtual table_map not_null_tables() const { return used_tables(); }
  /*
    Returns true if this is a simple constant item like an integer, not
449
    a constant expression. Used in the optimizer to propagate basic constants.
450
  */
unknown's avatar
unknown committed
451
  virtual bool basic_const_item() const { return 0; }
unknown's avatar
unknown committed
452 453
  /* cloning of constant items (0 if it is not const) */
  virtual Item *new_item() { return 0; }
unknown's avatar
unknown committed
454 455 456
  virtual cond_result eq_cmp_result() const { return COND_OK; }
  inline uint float_length(uint decimals_par) const
  { return decimals != NOT_FIXED_DEC ? (DBL_DIG+2+decimals_par) : DBL_DIG+8;}
unknown's avatar
unknown committed
457 458 459
  virtual uint decimal_precision() const;
  inline int decimal_int_part() const
  { return my_decimal_int_part(decimal_precision(), decimals); }
460 461 462 463
  /* 
    Returns true if this is constant (during query execution, i.e. its value
    will not change until next fix_fields) and its value is known.
  */
unknown's avatar
unknown committed
464
  virtual bool const_item() const { return used_tables() == 0; }
465 466 467 468 469 470
  /* 
    Returns true if this is constant but its value may be not known yet.
    (Can be used for parameters of prep. stmts or of stored procedures.)
  */
  virtual bool const_during_execution() const 
  { return (used_tables() & ~PARAM_TABLE_BIT) == 0; }
471 472 473 474 475 476 477 478 479 480 481 482
  /*
    This is an essential method for correct functioning of VIEWS.
    To save a view in an .frm file we need its unequivocal
    definition in SQL that takes into account sql_mode and
    environmental settings.  Currently such definition is restored
    by traversing through the parsed tree of a view and
    print()'ing SQL syntax of every node to a String buffer. This
    method is used to print the SQL definition of an item. The
    second use of this method is for EXPLAIN EXTENDED, to print
    the SQL of a query after all optimizations of the parsed tree
    have been done.
  */
unknown's avatar
unknown committed
483
  virtual void print(String *str_arg) { str_arg->append(full_name()); }
unknown's avatar
unknown committed
484
  void print_item_w_name(String *);
unknown's avatar
unknown committed
485
  virtual void update_used_tables() {}
486 487
  virtual void split_sum_func(THD *thd, Item **ref_pointer_array,
                              List<Item> &fields) {}
488 489 490
  /* Called for items that really have to be split */
  void split_sum_func2(THD *thd, Item **ref_pointer_array, List<Item> &fields,
                       Item **ref);
491
  virtual bool get_date(TIME *ltime,uint fuzzydate);
unknown's avatar
unknown committed
492
  virtual bool get_time(TIME *ltime);
493
  virtual bool get_date_result(TIME *ltime,uint fuzzydate)
494
  { return get_date(ltime,fuzzydate); }
495 496 497 498 499 500 501 502
  /*
    This function is used only in Item_func_isnull/Item_func_isnotnull
    (implementations of IS NULL/IS NOT NULL clauses). Item_func_is{not}null
    calls this method instead of one of val/result*() methods, which
    normally will set null_value. This allows to determine nullness of
    a complex expression without fully evaluating it.
    Any new item which can be NULL must implement this call.
  */
503
  virtual bool is_null() { return 0; }
unknown's avatar
unknown committed
504 505 506 507
  /*
    it is "top level" item of WHERE clause and we do not need correct NULL
    handling
  */
508
  virtual void top_level_item() {}
unknown's avatar
unknown committed
509 510
  /*
    set field of temporary table for Item which can be switched on temporary
unknown's avatar
unknown committed
511
    table during query processing (grouping and so on)
unknown's avatar
unknown committed
512
  */
unknown's avatar
unknown committed
513 514
  virtual void set_result_field(Field *field) {}
  virtual bool is_result_field() { return 0; }
unknown's avatar
unknown committed
515
  virtual bool is_bool_func() { return 0; }
unknown's avatar
unknown committed
516
  virtual void save_in_result_field(bool no_conversions) {}
unknown's avatar
unknown committed
517
  /*
unknown's avatar
unknown committed
518
    set value of aggregate function in case of no rows for grouping were found
unknown's avatar
unknown committed
519
  */
unknown's avatar
unknown committed
520
  virtual void no_rows_in_result() {}
521
  virtual Item *copy_or_same(THD *thd) { return this; }
522
  virtual Item *copy_andor_structure(THD *thd) { return this; }
unknown's avatar
unknown committed
523
  virtual Item *real_item() { return this; }
524
  virtual Item *get_tmp_table_item(THD *thd) { return copy_or_same(thd); }
unknown's avatar
unknown committed
525

526
  static CHARSET_INFO *default_charset();
527
  virtual CHARSET_INFO *compare_collation() { return NULL; }
unknown's avatar
unknown committed
528 529 530 531 532 533

  virtual bool walk(Item_processor processor, byte *arg)
  {
    return (this->*processor)(arg);
  }

534
  virtual Item* transform(Item_transformer transformer, byte *arg)
535
  {
unknown's avatar
unknown committed
536
    return (this->*transformer)(arg);
537
  }
538

539 540
   virtual void traverse_cond(Cond_traverser traverser,
                              void *arg, traverse_order order)
541 542 543
   {
     (*traverser)(this, arg);
   }
544

unknown's avatar
unknown committed
545
  virtual bool remove_dependence_processor(byte * arg) { return 0; }
546
  virtual bool remove_fixed(byte * arg) { fixed= 0; return 0; }
unknown's avatar
unknown committed
547
  virtual bool cleanup_processor(byte *arg);
548
  virtual bool collect_item_field_processor(byte * arg) { return 0; }
549
  virtual Item *equal_fields_propagator(byte * arg) { return this; }
unknown's avatar
unknown committed
550
  virtual Item *set_no_const_sub(byte *arg) { return this; }
unknown's avatar
unknown committed
551
  virtual Item *replace_equal_field(byte * arg) { return this; }
552 553 554 555 556 557 558 559 560 561 562

  /*
    For SP local variable returns pointer to Item representing its
    current value and pointer to current Item otherwise.
  */
  virtual Item *this_item() { return this; }
  /*
    For SP local variable returns address of pointer to Item representing its
    current value and pointer passed via parameter otherwise.
  */
  virtual Item **this_item_addr(THD *thd, Item **addr) { return addr; }
563
  virtual Item *this_const_item() const { return const_cast<Item*>(this); } /* For SPs mostly. */
unknown's avatar
unknown committed
564 565 566 567

  // Row emulation
  virtual uint cols() { return 1; }
  virtual Item* el(uint i) { return this; }
568
  virtual Item** addr(uint i) { return 0; }
unknown's avatar
unknown committed
569
  virtual bool check_cols(uint c);
unknown's avatar
unknown committed
570
  // It is not row => null inside is impossible
571 572 573
  virtual bool null_inside() { return 0; }
  // used in row subselects to get value of elements
  virtual void bring_value() {}
574 575

  Field *tmp_table_field_from_field_type(TABLE *table);
576
  virtual Item_field *filed_for_view_update() { return 0; }
unknown's avatar
unknown committed
577

578
  virtual Item *neg_transformer(THD *thd) { return NULL; }
unknown's avatar
unknown committed
579
  virtual Item *safe_charset_converter(CHARSET_INFO *tocs);
580 581 582 583
  void delete_self()
  {
    cleanup();
    delete this;
unknown's avatar
unknown committed
584
  }
585 586

  virtual bool is_splocal() { return 0; } /* Needed for error checking */
unknown's avatar
unknown committed
587 588 589
};


590 591 592 593 594 595
// A local SP variable (incl. parameters), used in runtime
class Item_splocal : public Item
{
private:
  
  uint m_offset;
unknown's avatar
unknown committed
596
  LEX_STRING m_name;
597 598 599

public:

unknown's avatar
unknown committed
600 601
  Item_splocal(LEX_STRING name, uint offset)
    : m_offset(offset), m_name(name)
602 603 604
  {
    Item::maybe_null= TRUE;
  }
605

606
  /* For error printing */
unknown's avatar
unknown committed
607
  inline LEX_STRING *my_name(LEX_STRING *get_name)
608
  {
unknown's avatar
unknown committed
609 610 611 612
    if (!get_name)
      return &m_name;
    (*get_name)= m_name;
    return get_name;
613 614
  }

615 616
  bool is_splocal() { return 1; } /* Needed for error checking */

617
  Item *this_item();
618
  Item **this_item_addr(THD *thd, Item **);
619 620
  Item *this_const_item() const;

unknown's avatar
unknown committed
621 622 623
  bool fix_fields(THD *, struct st_table_list *, Item **);
  void cleanup();

624 625 626 627 628 629 630
  inline uint get_offset()
  {
    return m_offset;
  }

  // Abstract methods inherited from Item. Just defer the call to
  // the item in the frame
631
  enum Type type() const;
632

unknown's avatar
unknown committed
633 634 635 636
  double val_real();
  longlong val_int();
  String *val_str(String *sp);
  my_decimal *val_decimal(my_decimal *);
637
  bool is_null();
unknown's avatar
unknown committed
638
  void print(String *str);
639 640 641

  inline void make_field(Send_field *field)
  {
642 643
    Item *it= this_item();

644
    if (name)
645
      it->set_name(name, (uint) strlen(name), system_charset_info);
646 647
    else
      it->set_name(m_name.str, m_name.length, system_charset_info);
648
    it->make_field(field);
649 650
  }

651 652 653 654 655 656 657
  inline Item_result result_type() const
  {
    return this_const_item()->result_type();
  }

  inline bool const_item() const
  {
658
    return TRUE;
659 660
  }

661 662 663 664
  inline int save_in_field(Field *field, bool no_conversions)
  {
    return this_item()->save_in_field(field, no_conversions);
  }
unknown's avatar
unknown committed
665

666 667 668 669
  inline bool send(Protocol *protocol, String *str)
  {
    return this_item()->send(protocol, str);
  }
670 671 672
};


673 674 675
class Item_num: public Item
{
public:
unknown's avatar
unknown committed
676
  virtual Item_num *neg()= 0;
677 678
};

679
#define NO_CACHED_FIELD_INDEX ((uint)(-1))
680

unknown's avatar
unknown committed
681
class st_select_lex;
unknown's avatar
unknown committed
682 683
class Item_ident :public Item
{
684
protected:
685 686 687 688 689 690 691 692 693
  /* 
    We have to store initial values of db_name, table_name and field_name
    to be able to restore them during cleanup() because they can be 
    updated during fix_fields() to values from Field object and life-time 
    of those is shorter than life-time of Item_field.
  */
  const char *orig_db_name;
  const char *orig_table_name;
  const char *orig_field_name;
unknown's avatar
unknown committed
694 695 696 697
public:
  const char *db_name;
  const char *table_name;
  const char *field_name;
unknown's avatar
unknown committed
698
  bool alias_name_used; /* true if item was resolved against alias */
699 700
  /* 
    Cached value of index for this field in table->field array, used by prep. 
701 702 703 704 705 706 707 708
    stmts for speeding up their re-execution. Holds NO_CACHED_FIELD_INDEX 
    if index value is not known.
  */
  uint cached_field_index;
  /*
    Cached pointer to table which contains this field, used for the same reason
    by prep. stmt. too in case then we have not-fully qualified field.
    0 - means no cached value.
709
  */
710
  TABLE_LIST *cached_table;
unknown's avatar
unknown committed
711
  st_select_lex *depended_from;
unknown's avatar
unknown committed
712
  Item_ident(const char *db_name_par,const char *table_name_par,
713
	     const char *field_name_par);
unknown's avatar
unknown committed
714
  Item_ident(THD *thd, Item_ident *item);
unknown's avatar
unknown committed
715
  const char *full_name() const;
716
  void cleanup();
unknown's avatar
unknown committed
717
  bool remove_dependence_processor(byte * arg);
718
  void print(String *str);
unknown's avatar
VIEW  
unknown committed
719 720 721

  friend bool insert_fields(THD *thd,TABLE_LIST *tables, const char *db_name,
                            const char *table_name, List_iterator<Item> *it,
unknown's avatar
unknown committed
722
                            bool any_privileges, bool allocate_view_names);
unknown's avatar
unknown committed
723 724
};

725 726
class Item_equal;
class COND_EQUAL;
unknown's avatar
unknown committed
727

unknown's avatar
unknown committed
728 729
class Item_field :public Item_ident
{
730
protected:
unknown's avatar
unknown committed
731 732 733
  void set_field(Field *field);
public:
  Field *field,*result_field;
unknown's avatar
unknown committed
734 735
  Item_equal *item_equal;
  bool no_const_subst;
unknown's avatar
VIEW  
unknown committed
736 737 738 739 740 741 742
  /*
    if any_privileges set to TRUE then here real effective privileges will
    be stored
  */
  uint have_privileges;
  /* field need any privileges (for VIEW creation) */
  bool any_privileges;
unknown's avatar
unknown committed
743 744 745

  Item_field(const char *db_par,const char *table_name_par,
	     const char *field_name_par)
746
    :Item_ident(db_par,table_name_par,field_name_par),
unknown's avatar
unknown committed
747
    field(0), result_field(0), item_equal(0), no_const_subst(0),
unknown's avatar
unknown committed
748
     have_privileges(0), any_privileges(0)
749
  { collation.set(DERIVATION_IMPLICIT); }
750 751 752
  /*
    Constructor needed to process subselect with temporary tables (see Item)
  */
753
  Item_field(THD *thd, Item_field *item);
754
  /*
755 756 757
    Constructor used inside setup_wild(), ensures that field, table,
    and database names will live as long as Item_field (this is important
    in prepared statements).
758 759
  */
  Item_field(THD *thd, Field *field);
760 761 762
  /*
    If this constructor is used, fix_fields() won't work, because
    db_name, table_name and column_name are unknown. It's necessary to call
763
    reset_field() before fix_fields() for all fields created this way.
764
  */
unknown's avatar
unknown committed
765 766
  Item_field(Field *field);
  enum Type type() const { return FIELD_ITEM; }
767
  bool eq(const Item *item, bool binary_cmp) const;
768
  double val_real();
unknown's avatar
unknown committed
769
  longlong val_int();
unknown's avatar
unknown committed
770
  my_decimal *val_decimal(my_decimal *);
unknown's avatar
unknown committed
771 772 773 774
  String *val_str(String*);
  double val_result();
  longlong val_int_result();
  String *str_result(String* tmp);
unknown's avatar
unknown committed
775 776
  my_decimal *val_decimal_result(my_decimal *);
  bool val_bool_result();
777
  bool send(Protocol *protocol, String *str_arg);
778
  void reset_field(Field *f);
unknown's avatar
unknown committed
779
  bool fix_fields(THD *, struct st_table_list *, Item **);
780
  void make_field(Send_field *tmp_field);
unknown's avatar
unknown committed
781
  int save_in_field(Field *field,bool no_conversions);
unknown's avatar
unknown committed
782 783 784 785 786 787
  void save_org_in_field(Field *field);
  table_map used_tables() const;
  enum Item_result result_type () const
  {
    return field->result_type();
  }
788 789 790 791
  Item_result cast_to_int_type() const
  {
    return field->cast_to_int_type();
  }
unknown's avatar
unknown committed
792
  enum_field_types field_type() const
793 794 795
  {
    return field->type();
  }
796
  Field *get_tmp_table_field() { return result_field; }
797
  Field *tmp_table_field(TABLE *t_arg) { return result_field; }
798 799
  bool get_date(TIME *ltime,uint fuzzydate);
  bool get_date_result(TIME *ltime,uint fuzzydate);
800
  bool get_time(TIME *ltime);
unknown's avatar
unknown committed
801
  bool is_null() { return field->is_null(); }
802
  Item *get_tmp_table_item(THD *thd);
803
  bool collect_item_field_processor(byte * arg);
unknown's avatar
unknown committed
804
  void cleanup();
805 806
  Item_equal *find_item_equal(COND_EQUAL *cond_equal);
  Item *equal_fields_propagator(byte *arg);
unknown's avatar
unknown committed
807
  Item *set_no_const_sub(byte *arg);
unknown's avatar
unknown committed
808
  Item *replace_equal_field(byte *arg);
unknown's avatar
unknown committed
809
  inline uint32 max_disp_length() { return field->max_length(); }
810
  Item_field *filed_for_view_update() { return this; }
unknown's avatar
unknown committed
811
  Item *safe_charset_converter(CHARSET_INFO *tocs);
unknown's avatar
SCRUM  
unknown committed
812
  friend class Item_default_value;
unknown's avatar
unknown committed
813
  friend class Item_insert_value;
unknown's avatar
unknown committed
814
  friend class st_select_lex_unit;
unknown's avatar
unknown committed
815 816 817 818 819 820
};

class Item_null :public Item
{
public:
  Item_null(char *name_par=0)
unknown's avatar
unknown committed
821 822 823 824 825
  {
    maybe_null= null_value= TRUE;
    max_length= 0;
    name= name_par ? name_par : (char*) "NULL";
    fixed= 1;
826
    collation.set(&my_charset_bin, DERIVATION_IGNORABLE);
unknown's avatar
unknown committed
827
  }
unknown's avatar
unknown committed
828
  enum Type type() const { return NULL_ITEM; }
829
  bool eq(const Item *item, bool binary_cmp) const;
830
  double val_real();
unknown's avatar
unknown committed
831 832
  longlong val_int();
  String *val_str(String *str);
unknown's avatar
unknown committed
833
  my_decimal *val_decimal(my_decimal *);
unknown's avatar
unknown committed
834
  int save_in_field(Field *field, bool no_conversions);
unknown's avatar
unknown committed
835
  int save_safe_in_field(Field *field);
unknown's avatar
unknown committed
836
  bool send(Protocol *protocol, String *str);
837 838
  enum Item_result result_type () const { return STRING_RESULT; }
  enum_field_types field_type() const   { return MYSQL_TYPE_NULL; }
unknown's avatar
unknown committed
839
  /* to prevent drop fixed flag (no need parent cleanup call) */
unknown's avatar
unknown committed
840
  void cleanup() {}
unknown's avatar
unknown committed
841 842
  bool basic_const_item() const { return 1; }
  Item *new_item() { return new Item_null(name); }
unknown's avatar
unknown committed
843
  bool is_null() { return 1; }
844
  void print(String *str) { str->append("NULL", 4); }
unknown's avatar
unknown committed
845
  Item *safe_charset_converter(CHARSET_INFO *tocs);
unknown's avatar
unknown committed
846 847
};

unknown's avatar
unknown committed
848 849 850 851 852 853 854 855 856 857 858
class Item_null_result :public Item_null
{
public:
  Field *result_field;
  Item_null_result() : Item_null(), result_field(0) {}
  bool is_result_field() { return result_field != 0; }
  void save_in_result_field(bool no_conversions)
  {
    save_in_field(result_field, no_conversions);
  }
};  
859 860 861

/* Item represents one placeholder ('?') of prepared statement */

unknown's avatar
unknown committed
862 863
class Item_param :public Item
{
864
public:
865 866 867
  enum enum_item_param_state
  {
    NO_VALUE, NULL_VALUE, INT_VALUE, REAL_VALUE,
unknown's avatar
unknown committed
868 869
    STRING_VALUE, TIME_VALUE, LONG_DATA_VALUE,
    DECIMAL_VALUE
870 871
  } state;

872 873 874 875 876 877 878 879 880 881 882
  /*
    A buffer for string and long data values. Historically all allocated
    values returned from val_str() were treated as eligible to
    modification. I. e. in some cases Item_func_concat can append it's
    second argument to return value of the first one. Because of that we
    can't return the original buffer holding string data from val_str(),
    and have to have one buffer for data and another just pointing to
    the data. This is the latter one and it's returned from val_str().
    Can not be declared inside the union as it's not a POD type.
  */
  String str_value_ptr;
unknown's avatar
unknown committed
883
  my_decimal decimal_value;
884 885
  union
  {
886 887
    longlong integer;
    double   real;
888 889 890 891 892 893 894 895 896 897 898 899
    /*
      Character sets conversion info for string values.
      Character sets of client and connection defined at bind time are used
      for all conversions, even if one of them is later changed (i.e.
      between subsequent calls to mysql_stmt_execute).
    */
    struct CONVERSION_INFO
    {
      CHARSET_INFO *character_set_client;
      /*
        This points at character set of connection if conversion
        to it is required (i. e. if placeholder typecode is not BLOB).
900
        Otherwise it's equal to character_set_client (to simplify
901 902 903 904 905 906 907 908
        check in convert_str_value()).
      */
      CHARSET_INFO *final_character_set_of_str_value;
    } cs_info;
    TIME     time;
  } value;

  /* Cached values for virtual methods to save us one switch.  */
unknown's avatar
unknown committed
909 910
  enum Item_result item_result_type;
  enum Type item_type;
911 912 913 914 915 916 917 918 919 920

  /*
    Used when this item is used in a temporary table.
    This is NOT placeholder metadata sent to client, as this value
    is assigned after sending metadata (in setup_one_conversion_function).
    For example in case of 'SELECT ?' you'll get MYSQL_TYPE_STRING both
    in result set and placeholders metadata, no matter what type you will
    supply for this placeholder in mysql_stmt_execute.
  */
  enum enum_field_types param_type;
921
  /*
922 923
    Offset of placeholder inside statement text. Used to create
    no-placeholders version of this statement for the binary log.
924
  */
925
  uint pos_in_query;
unknown's avatar
unknown committed
926

927 928 929
  Item_param(uint pos_in_query_arg);

  enum Item_result result_type () const { return item_result_type; }
unknown's avatar
unknown committed
930
  enum Type type() const { return item_type; }
931
  enum_field_types field_type() const { return param_type; }
932

933
  double val_real();
unknown's avatar
unknown committed
934
  longlong val_int();
unknown's avatar
unknown committed
935
  my_decimal *val_decimal(my_decimal*);
unknown's avatar
unknown committed
936
  String *val_str(String*);
937
  bool get_time(TIME *tm);
938
  bool get_date(TIME *tm, uint fuzzydate);
unknown's avatar
unknown committed
939
  int  save_in_field(Field *field, bool no_conversions);
unknown's avatar
unknown committed
940
  bool fix_fields(THD *, struct st_table_list *, Item **);
941

unknown's avatar
unknown committed
942
  void set_null();
943
  void set_int(longlong i, uint32 max_length_arg);
unknown's avatar
unknown committed
944
  void set_double(double i);
unknown's avatar
unknown committed
945
  void set_decimal(const char *str, ulong length);
946 947 948
  bool set_str(const char *str, ulong length);
  bool set_longdata(const char *str, ulong length);
  void set_time(TIME *tm, timestamp_type type, uint32 max_length_arg);
949
  bool set_from_user_var(THD *thd, const user_var_entry *entry);
950
  void reset();
951 952 953 954 955 956 957 958
  /*
    Assign placeholder value from bind data.
    Note, that 'len' has different semantics in embedded library (as we
    don't need to check that packet is not broken there). See
    sql_prepare.cc for details.
  */
  void (*set_param_func)(Item_param *param, uchar **pos, ulong len);

959 960 961
  const String *query_val_str(String *str) const;

  bool convert_str_value(THD *thd);
962 963 964 965

  /*
    If value for parameter was not set we treat it as non-const
    so noone will use parameters value in fix_fields still
966 967 968
    parameter is constant during execution.
  */
  virtual table_map used_tables() const
969
  { return state != NO_VALUE ? (table_map)0 : PARAM_TABLE_BIT; }
970
  void print(String *str);
971 972
  bool is_null()
  { DBUG_ASSERT(state != NO_VALUE); return state == NULL_VALUE; }
973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990
  bool basic_const_item() const;
  /*
    This method is used to make a copy of a basic constant item when
    propagating constants in the optimizer. The reason to create a new
    item and not use the existing one is not precisely known (2005/04/16).
    Probably we are trying to preserve tree structure of items, in other
    words, avoid pointing at one item from two different nodes of the tree.
    Return a new basic constant item if parameter value is a basic
    constant, assert otherwise. This method is called only if
    basic_const_item returned TRUE.
  */
  Item *new_item();
  /*
    Implement by-value equality evaluation if parameter value
    is set and is a basic constant (integer, real or string).
    Otherwise return FALSE.
  */
  bool eq(const Item *item, bool binary_cmp) const;
unknown's avatar
unknown committed
991
};
unknown's avatar
unknown committed
992

993

994
class Item_int :public Item_num
unknown's avatar
unknown committed
995 996
{
public:
997
  longlong value;
unknown's avatar
unknown committed
998
  Item_int(int32 i,uint length=11) :value((longlong) i)
999
    { max_length=length; fixed= 1; }
unknown's avatar
unknown committed
1000
  Item_int(longlong i,uint length=21) :value(i)
unknown's avatar
unknown committed
1001
    { max_length=length; fixed= 1; }
1002 1003
  Item_int(ulonglong i, uint length= 21) :value((longlong)i)
    { max_length=length; fixed= 1; unsigned_flag= 1; }
unknown's avatar
unknown committed
1004
  Item_int(const char *str_arg,longlong i,uint length) :value(i)
1005
    { max_length=length; name=(char*) str_arg; fixed= 1; }
unknown's avatar
unknown committed
1006
  Item_int(const char *str_arg, uint length=64);
unknown's avatar
unknown committed
1007
  enum Type type() const { return INT_ITEM; }
1008 1009
  enum Item_result result_type () const { return INT_RESULT; }
  enum_field_types field_type() const { return MYSQL_TYPE_LONGLONG; }
1010
  longlong val_int() { DBUG_ASSERT(fixed == 1); return value; }
1011
  double val_real() { DBUG_ASSERT(fixed == 1); return (double) value; }
unknown's avatar
unknown committed
1012
  my_decimal *val_decimal(my_decimal *);
unknown's avatar
unknown committed
1013
  String *val_str(String*);
unknown's avatar
unknown committed
1014
  int save_in_field(Field *field, bool no_conversions);
unknown's avatar
unknown committed
1015 1016
  bool basic_const_item() const { return 1; }
  Item *new_item() { return new Item_int(name,value,max_length); }
1017
  // to prevent drop fixed flag (no need parent cleanup call)
unknown's avatar
unknown committed
1018
  void cleanup() {}
unknown's avatar
unknown committed
1019
  void print(String *str);
unknown's avatar
unknown committed
1020
  Item_num *neg() { value= -value; return this; }
unknown's avatar
unknown committed
1021
  uint decimal_precision() const { return (uint)(max_length - test(value < 0)); }
1022
  bool eq(const Item *, bool binary_cmp) const;
unknown's avatar
unknown committed
1023 1024 1025
};


1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036
class Item_static_int_func :public Item_int
{
  const char *func_name;
public:
  Item_static_int_func(const char *str_arg, longlong i, uint length)
    :Item_int(NullS, i, length), func_name(str_arg)
  {}
  void print(String *str) { str->append(func_name); }
};


unknown's avatar
unknown committed
1037 1038 1039
class Item_uint :public Item_int
{
public:
unknown's avatar
unknown committed
1040
  Item_uint(const char *str_arg, uint length);
1041
  Item_uint(uint32 i) :Item_int((ulonglong) i, 10) {}
1042
  Item_uint(const char *str_arg, longlong i, uint length);
1043
  double val_real()
1044
    { DBUG_ASSERT(fixed == 1); return ulonglong2double((ulonglong)value); }
unknown's avatar
unknown committed
1045 1046
  String *val_str(String*);
  Item *new_item() { return new Item_uint(name,max_length); }
unknown's avatar
unknown committed
1047
  int save_in_field(Field *field, bool no_conversions);
unknown's avatar
unknown committed
1048
  void print(String *str);
unknown's avatar
unknown committed
1049
  Item_num *neg ();
unknown's avatar
unknown committed
1050
  uint decimal_precision() const { return max_length; }
unknown's avatar
unknown committed
1051 1052 1053
};


unknown's avatar
unknown committed
1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089
/* decimal (fixed point) constant */
class Item_decimal :public Item_num
{
protected:
  my_decimal decimal_value;
public:
  Item_decimal(const char *str_arg, uint length, CHARSET_INFO *charset);
  Item_decimal(const char *str, const my_decimal *val_arg,
               uint decimal_par, uint length);
  Item_decimal(my_decimal *value_par);
  Item_decimal(longlong val, bool unsig);
  Item_decimal(double val, int precision, int scale);
  Item_decimal(const char *bin, int precision, int scale);

  enum Type type() const { return DECIMAL_ITEM; }
  enum Item_result result_type () const { return DECIMAL_RESULT; }
  enum_field_types field_type() const { return MYSQL_TYPE_NEWDECIMAL; }
  longlong val_int();
  double val_real();
  String *val_str(String*);
  my_decimal *val_decimal(my_decimal *val) { return &decimal_value; }
  int save_in_field(Field *field, bool no_conversions);
  bool basic_const_item() const { return 1; }
  Item *new_item()
  {
    return new Item_decimal(name, &decimal_value, decimals, max_length);
  }
  // to prevent drop fixed flag (no need parent cleanup call)
  void cleanup() {}
  void print(String *str);
  Item_num *neg()
  {
    my_decimal_neg(&decimal_value);
    unsigned_flag= !decimal_value.sign();
    return this;
  }
unknown's avatar
unknown committed
1090
  uint decimal_precision() const { return decimal_value.precision(); }
1091
  bool eq(const Item *, bool binary_cmp) const;
unknown's avatar
unknown committed
1092 1093
};

1094

unknown's avatar
unknown committed
1095
class Item_float :public Item_num
unknown's avatar
unknown committed
1096
{
1097
  char *presentation;
unknown's avatar
unknown committed
1098
public:
1099
  double value;
unknown's avatar
unknown committed
1100
  // Item_real() :value(0) {}
unknown's avatar
unknown committed
1101 1102
  Item_float(const char *str_arg, uint length);
  Item_float(const char *str,double val_arg,uint decimal_par,uint length)
unknown's avatar
unknown committed
1103 1104
    :value(val_arg)
  {
1105
    presentation= name=(char*) str;
unknown's avatar
unknown committed
1106
    decimals=(uint8) decimal_par;
unknown's avatar
unknown committed
1107
    max_length=length;
unknown's avatar
unknown committed
1108
    fixed= 1;
unknown's avatar
unknown committed
1109
  }
unknown's avatar
unknown committed
1110 1111
  Item_float(double value_par) :presentation(0), value(value_par) { fixed= 1; }

unknown's avatar
unknown committed
1112
  int save_in_field(Field *field, bool no_conversions);
unknown's avatar
unknown committed
1113
  enum Type type() const { return REAL_ITEM; }
1114
  enum_field_types field_type() const { return MYSQL_TYPE_DOUBLE; }
1115
  double val_real() { DBUG_ASSERT(fixed == 1); return value; }
1116 1117 1118 1119 1120
  longlong val_int()
  {
    DBUG_ASSERT(fixed == 1);
    return (longlong) (value+(value > 0 ? 0.5 : -0.5));
  }
unknown's avatar
unknown committed
1121
  String *val_str(String*);
unknown's avatar
unknown committed
1122
  my_decimal *val_decimal(my_decimal *);
unknown's avatar
unknown committed
1123
  bool basic_const_item() const { return 1; }
unknown's avatar
unknown committed
1124 1125
  // to prevent drop fixed flag (no need parent cleanup call)
  void cleanup() {}
unknown's avatar
unknown committed
1126 1127
  Item *new_item()
  { return new Item_float(name, value, decimals, max_length); }
unknown's avatar
unknown committed
1128
  Item_num *neg() { value= -value; return this; }
1129
  void print(String *str);
1130
  bool eq(const Item *, bool binary_cmp) const;
unknown's avatar
unknown committed
1131 1132 1133
};


unknown's avatar
unknown committed
1134
class Item_static_float_func :public Item_float
1135 1136 1137
{
  const char *func_name;
public:
unknown's avatar
unknown committed
1138
  Item_static_float_func(const char *str, double val_arg, uint decimal_par,
1139
                        uint length)
unknown's avatar
unknown committed
1140
    :Item_float(NullS, val_arg, decimal_par, length), func_name(str)
1141 1142 1143 1144 1145
  {}
  void print(String *str) { str->append(func_name); }
};


unknown's avatar
unknown committed
1146 1147 1148
class Item_string :public Item
{
public:
unknown's avatar
unknown committed
1149
  Item_string(const char *str,uint length,
1150
  	      CHARSET_INFO *cs, Derivation dv= DERIVATION_COERCIBLE)
unknown's avatar
unknown committed
1151
  {
1152
    collation.set(cs, dv);
unknown's avatar
unknown committed
1153
    str_value.set_or_copy_aligned(str,length,cs);
1154 1155 1156 1157 1158 1159 1160
    /*
      We have to have a different max_length than 'length' here to
      ensure that we get the right length if we do use the item
      to create a new table. In this case max_length must be the maximum
      number of chars for a string of this type because we in create_field::
      divide the max_length with mbmaxlen).
    */
1161
    max_length= str_value.numchars()*cs->mbmaxlen;
unknown's avatar
unknown committed
1162
    set_name(str, length, cs);
unknown's avatar
unknown committed
1163
    decimals=NOT_FIXED_DEC;
1164 1165
    // it is constant => can be used without fix_fields (and frequently used)
    fixed= 1;
unknown's avatar
unknown committed
1166
  }
1167
  Item_string(const char *name_par, const char *str, uint length,
1168
	      CHARSET_INFO *cs, Derivation dv= DERIVATION_COERCIBLE)
unknown's avatar
unknown committed
1169
  {
1170
    collation.set(cs, dv);
unknown's avatar
unknown committed
1171
    str_value.set_or_copy_aligned(str,length,cs);
1172
    max_length= str_value.numchars()*cs->mbmaxlen;
unknown's avatar
unknown committed
1173
    set_name(name_par,0,cs);
unknown's avatar
unknown committed
1174
    decimals=NOT_FIXED_DEC;
1175 1176
    // it is constant => can be used without fix_fields (and frequently used)
    fixed= 1;
unknown's avatar
unknown committed
1177 1178
  }
  enum Type type() const { return STRING_ITEM; }
1179 1180
  double val_real();
  longlong val_int();
1181 1182 1183 1184 1185
  String *val_str(String*)
  {
    DBUG_ASSERT(fixed == 1);
    return (String*) &str_value;
  }
unknown's avatar
unknown committed
1186
  my_decimal *val_decimal(my_decimal *);
unknown's avatar
unknown committed
1187
  int save_in_field(Field *field, bool no_conversions);
unknown's avatar
unknown committed
1188
  enum Item_result result_type () const { return STRING_RESULT; }
1189
  enum_field_types field_type() const { return MYSQL_TYPE_VARCHAR; }
unknown's avatar
unknown committed
1190
  bool basic_const_item() const { return 1; }
1191
  bool eq(const Item *item, bool binary_cmp) const;
1192 1193
  Item *new_item() 
  {
1194
    return new Item_string(name, str_value.ptr(), 
unknown's avatar
unknown committed
1195
    			   str_value.length(), collation.collation);
1196
  }
unknown's avatar
unknown committed
1197
  Item *safe_charset_converter(CHARSET_INFO *tocs);
unknown's avatar
unknown committed
1198
  String *const_string() { return &str_value; }
1199
  inline void append(char *str, uint length) { str_value.append(str, length); }
unknown's avatar
unknown committed
1200
  void print(String *str);
unknown's avatar
unknown committed
1201 1202
  // to prevent drop fixed flag (no need parent cleanup call)
  void cleanup() {}
unknown's avatar
unknown committed
1203 1204
};

1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218

class Item_static_string_func :public Item_string
{
  const char *func_name;
public:
  Item_static_string_func(const char *name_par, const char *str, uint length,
                          CHARSET_INFO *cs,
                          Derivation dv= DERIVATION_COERCIBLE)
    :Item_string(NullS, str, length, cs, dv), func_name(name_par)
  {}
  void print(String *str) { str->append(func_name); }
};


unknown's avatar
unknown committed
1219 1220 1221 1222 1223
/* for show tables */

class Item_datetime :public Item_string
{
public:
unknown's avatar
unknown committed
1224
  Item_datetime(const char *item_name): Item_string(item_name,"",0,
unknown's avatar
unknown committed
1225
                                                    &my_charset_bin)
unknown's avatar
unknown committed
1226
  { max_length=19;}
1227
  enum_field_types field_type() const { return MYSQL_TYPE_DATETIME; }
unknown's avatar
unknown committed
1228 1229 1230 1231 1232
};

class Item_empty_string :public Item_string
{
public:
1233 1234
  Item_empty_string(const char *header,uint length, CHARSET_INFO *cs= NULL) :
    Item_string("",0, cs ? cs : &my_charset_bin)
1235
    { name=(char*) header; max_length= cs ? length * cs->mbmaxlen : length; }
1236
  void make_field(Send_field *field);
unknown's avatar
unknown committed
1237 1238
};

1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252
class Item_return_int :public Item_int
{
  enum_field_types int_field_type;
public:
  Item_return_int(const char *name, uint length,
		  enum_field_types field_type_arg)
    :Item_int(name, 0, length), int_field_type(field_type_arg)
  {
    unsigned_flag=1;
  }
  enum_field_types field_type() const { return int_field_type; }
};


unknown's avatar
unknown committed
1253
class Item_hex_string: public Item
unknown's avatar
unknown committed
1254 1255
{
public:
unknown's avatar
unknown committed
1256 1257
  Item_hex_string(): Item() {}
  Item_hex_string(const char *str,uint str_length);
unknown's avatar
unknown committed
1258
  enum Type type() const { return VARBIN_ITEM; }
1259
  double val_real()
unknown's avatar
unknown committed
1260
    { DBUG_ASSERT(fixed == 1); return (double) Item_hex_string::val_int(); }
unknown's avatar
unknown committed
1261
  longlong val_int();
unknown's avatar
unknown committed
1262
  bool basic_const_item() const { return 1; }
1263
  String *val_str(String*) { DBUG_ASSERT(fixed == 1); return &str_value; }
unknown's avatar
unknown committed
1264
  my_decimal *val_decimal(my_decimal *);
unknown's avatar
unknown committed
1265
  int save_in_field(Field *field, bool no_conversions);
1266
  enum Item_result result_type () const { return STRING_RESULT; }
1267
  enum_field_types field_type() const { return MYSQL_TYPE_VARCHAR; }
unknown's avatar
unknown committed
1268 1269
  // to prevent drop fixed flag (no need parent cleanup call)
  void cleanup() {}
1270
  bool eq(const Item *item, bool binary_cmp) const;
unknown's avatar
unknown committed
1271 1272 1273
};


unknown's avatar
unknown committed
1274 1275 1276 1277 1278 1279
class Item_bin_string: public Item_hex_string
{
public:
  Item_bin_string(const char *str,uint str_length);
};

unknown's avatar
unknown committed
1280 1281 1282 1283 1284
class Item_result_field :public Item	/* Item with result field */
{
public:
  Field *result_field;				/* Save result here */
  Item_result_field() :result_field(0) {}
1285
  // Constructor used for Item_sum/Item_cond_and/or (see Item comment)
1286 1287
  Item_result_field(THD *thd, Item_result_field *item):
    Item(thd, item), result_field(item->result_field)
1288
  {}
unknown's avatar
unknown committed
1289
  ~Item_result_field() {}			/* Required with gcc 2.95 */
1290
  Field *get_tmp_table_field() { return result_field; }
1291
  Field *tmp_table_field(TABLE *t_arg) { return result_field; }
unknown's avatar
unknown committed
1292
  table_map used_tables() const { return 1; }
unknown's avatar
unknown committed
1293
  virtual void fix_length_and_dec()=0;
unknown's avatar
unknown committed
1294 1295 1296 1297 1298 1299
  void set_result_field(Field *field) { result_field= field; }
  bool is_result_field() { return 1; }
  void save_in_result_field(bool no_conversions)
  {
    save_in_field(result_field, no_conversions);
  }
1300
  void cleanup();
unknown's avatar
unknown committed
1301 1302 1303 1304 1305
};


class Item_ref :public Item_ident
{
1306 1307
protected:
  void set_properties();
unknown's avatar
unknown committed
1308
public:
unknown's avatar
unknown committed
1309
  Field *result_field;			 /* Save result here */
unknown's avatar
unknown committed
1310
  Item **ref;
1311 1312
  Item_ref(const char *db_par, const char *table_name_par,
           const char *field_name_par)
unknown's avatar
unknown committed
1313
    :Item_ident(db_par, table_name_par, field_name_par), result_field(0), ref(0) {}
1314
  /*
1315 1316 1317 1318 1319 1320 1321 1322 1323 1324
    This constructor is used in two scenarios:
    A) *item = NULL
      No initialization is performed, fix_fields() call will be necessary.
      
    B) *item points to an Item this Item_ref will refer to. This is 
      used for GROUP BY. fix_fields() will not be called in this case,
      so we call set_properties to make this item "fixed". set_properties
      performs a subset of action Item_ref::fix_fields does, and this subset
      is enough for Item_ref's used in GROUP BY.
    
1325 1326 1327
    TODO we probably fix a superset of problems like in BUG#6658. Check this 
         with Bar, and if we have a more broader set of problems like this.
  */
unknown's avatar
unknown committed
1328
  Item_ref(Item **item, const char *table_name_par, const char *field_name_par);
1329

1330
  /* Constructor need to process subselect with temporary tables (see Item) */
unknown's avatar
unknown committed
1331
  Item_ref(THD *thd, Item_ref *item) :Item_ident(thd, item), result_field(item->result_field), ref(item->ref) {}
unknown's avatar
unknown committed
1332
  enum Type type() const		{ return REF_ITEM; }
1333
  bool eq(const Item *item, bool binary_cmp) const
unknown's avatar
unknown committed
1334
  { return ref && (*ref)->eq(item, binary_cmp); }
unknown's avatar
unknown committed
1335 1336 1337 1338 1339 1340 1341
  double val_real();
  longlong val_int();
  my_decimal *val_decimal(my_decimal *);
  bool val_bool();
  String *val_str(String* tmp);
  bool is_null();
  bool get_date(TIME *ltime,uint fuzzydate);
1342 1343 1344
  double val_result();
  longlong val_int_result();
  String *str_result(String* tmp);
unknown's avatar
unknown committed
1345 1346
  my_decimal *val_decimal_result(my_decimal *);
  bool val_bool_result();
1347
  bool send(Protocol *prot, String *tmp);
unknown's avatar
unknown committed
1348
  void make_field(Send_field *field)	{ (*ref)->make_field(field); }
unknown's avatar
unknown committed
1349
  bool fix_fields(THD *, struct st_table_list *, Item **);
unknown's avatar
unknown committed
1350
  int save_in_field(Field *field, bool no_conversions)
1351
  { return (*ref)->save_in_field(field, no_conversions); }
unknown's avatar
unknown committed
1352 1353
  void save_org_in_field(Field *field)	{ (*ref)->save_org_in_field(field); }
  enum Item_result result_type () const { return (*ref)->result_type(); }
1354
  enum_field_types field_type() const   { return (*ref)->field_type(); }
1355
  Field *get_tmp_table_field() { return result_field; }
1356 1357 1358 1359
  table_map used_tables() const		
  { 
    return depended_from ? OUTER_REF_TABLE_BIT : (*ref)->used_tables(); 
  }
1360
  table_map not_null_tables() const { return (*ref)->not_null_tables(); }
1361
  void set_result_field(Field *field)	{ result_field= field; }
unknown's avatar
unknown committed
1362 1363 1364 1365 1366
  bool is_result_field() { return 1; }
  void save_in_result_field(bool no_conversions)
  {
    (*ref)->save_in_field(result_field, no_conversions);
  }
unknown's avatar
unknown committed
1367 1368 1369
  Item *real_item()
  {
    return (*ref)->real_item();
1370
  }
1371 1372
  bool walk(Item_processor processor, byte *arg)
  { return (*ref)->walk(processor, arg); }
unknown's avatar
unknown committed
1373
  void print(String *str);
unknown's avatar
unknown committed
1374
  void cleanup();
unknown's avatar
unknown committed
1375 1376
};

1377

unknown's avatar
unknown committed
1378 1379 1380 1381
/*
  The same as Item_ref, but get value from val_* family of method to get
  value of item on which it referred instead of result* family.
*/
1382 1383 1384 1385 1386 1387 1388 1389
class Item_direct_ref :public Item_ref
{
public:
  Item_direct_ref(Item **item, const char *table_name_par,
                  const char *field_name_par)
    :Item_ref(item, table_name_par, field_name_par) {}
  /* Constructor need to process subselect with temporary tables (see Item) */
  Item_direct_ref(THD *thd, Item_direct_ref *item) : Item_ref(thd, item) {}
1390

unknown's avatar
unknown committed
1391 1392 1393 1394 1395 1396 1397
  double val_real();
  longlong val_int();
  String *val_str(String* tmp);
  my_decimal *val_decimal(my_decimal *);
  bool val_bool();
  bool is_null();
  bool get_date(TIME *ltime,uint fuzzydate);
1398 1399 1400
};


1401
class Item_in_subselect;
1402

1403 1404 1405 1406 1407 1408
class Item_ref_null_helper: public Item_ref
{
protected:
  Item_in_subselect* owner;
public:
  Item_ref_null_helper(Item_in_subselect* master, Item **item,
unknown's avatar
unknown committed
1409
		       const char *table_name_par, const char *field_name_par):
1410
    Item_ref(item, table_name_par, field_name_par), owner(master) {}
1411
  double val_real();
1412 1413
  longlong val_int();
  String* val_str(String* s);
unknown's avatar
unknown committed
1414 1415
  my_decimal *val_decimal(my_decimal *);
  bool val_bool();
1416
  bool get_date(TIME *ltime, uint fuzzydate);
unknown's avatar
unknown committed
1417
  void print(String *str);
1418 1419
};

1420 1421 1422 1423 1424 1425
class Item_null_helper :public Item_ref_null_helper
{
  Item *store;
public:
  Item_null_helper(Item_in_subselect* master, Item *item,
		   const char *table_name_par, const char *field_name_par)
unknown's avatar
unknown committed
1426 1427
    :Item_ref_null_helper(master, (store= 0, &store), table_name_par,
                          field_name_par),
1428
     store(item)
1429
    { ref= &store; }
unknown's avatar
unknown committed
1430
  void print(String *str);
1431
};
unknown's avatar
unknown committed
1432

1433

1434
/*
1435
  The following class is used to optimize comparing of date and bigint columns
1436 1437 1438 1439 1440
  We need to save the original item ('ref') to be able to call
  ref->save_in_field(). This is used to create index search keys.
  
  An instance of Item_int_with_ref may have signed or unsigned integer value.
  
1441 1442 1443 1444 1445 1446 1447
*/

class Item_int_with_ref :public Item_int
{
  Item *ref;
public:
  Item_int_with_ref(longlong i, Item *ref_arg) :Item_int(i), ref(ref_arg)
1448 1449 1450
  {
    unsigned_flag= ref_arg->unsigned_flag;
  }
unknown's avatar
unknown committed
1451
  int save_in_field(Field *field, bool no_conversions)
1452
  {
1453
    return ref->save_in_field(field, no_conversions);
1454
  }
1455
  Item *new_item();
1456 1457 1458
};


1459
#include "gstream.h"
unknown's avatar
unknown committed
1460
#include "spatial.h"
unknown's avatar
unknown committed
1461 1462
#include "item_sum.h"
#include "item_func.h"
1463
#include "item_row.h"
unknown's avatar
unknown committed
1464 1465
#include "item_cmpfunc.h"
#include "item_strfunc.h"
1466
#include "item_geofunc.h"
unknown's avatar
unknown committed
1467 1468
#include "item_timefunc.h"
#include "item_uniq.h"
1469
#include "item_subselect.h"
unknown's avatar
unknown committed
1470 1471 1472

class Item_copy_string :public Item
{
1473
  enum enum_field_types cached_field_type;
unknown's avatar
unknown committed
1474 1475 1476 1477 1478 1479 1480 1481
public:
  Item *item;
  Item_copy_string(Item *i) :item(i)
  {
    null_value=maybe_null=item->maybe_null;
    decimals=item->decimals;
    max_length=item->max_length;
    name=item->name;
1482
    cached_field_type= item->field_type();
unknown's avatar
unknown committed
1483 1484 1485
  }
  enum Type type() const { return COPY_STR_ITEM; }
  enum Item_result result_type () const { return STRING_RESULT; }
1486
  enum_field_types field_type() const { return cached_field_type; }
1487
  double val_real()
1488
  {
unknown's avatar
unknown committed
1489 1490
    int err_not_used;
    char *end_not_used;
1491 1492
    return (null_value ? 0.0 :
	    my_strntod(str_value.charset(), (char*) str_value.ptr(),
unknown's avatar
unknown committed
1493
		       str_value.length(), &end_not_used, &err_not_used));
1494
  }
unknown's avatar
unknown committed
1495
  longlong val_int()
1496 1497 1498 1499
  { 
    int err;
    return null_value ? LL(0) : my_strntoll(str_value.charset(),str_value.ptr(),str_value.length(),10, (char**) 0,&err); 
  }
unknown's avatar
unknown committed
1500
  String *val_str(String*);
unknown's avatar
unknown committed
1501
  my_decimal *val_decimal(my_decimal *);
unknown's avatar
unknown committed
1502 1503
  void make_field(Send_field *field) { item->make_field(field); }
  void copy();
unknown's avatar
unknown committed
1504
  int save_in_field(Field *field, bool no_conversions);
unknown's avatar
unknown committed
1505 1506
  table_map used_tables() const { return (table_map) 1L; }
  bool const_item() const { return 0; }
unknown's avatar
unknown committed
1507
  bool is_null() { return null_value; }
unknown's avatar
unknown committed
1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524
};


class Item_buff :public Sql_alloc
{
public:
  my_bool null_value;
  Item_buff() :null_value(0) {}
  virtual bool cmp(void)=0;
  virtual ~Item_buff(); /*line -e1509 */
};

class Item_str_buff :public Item_buff
{
  Item *item;
  String value,tmp_value;
public:
1525
  Item_str_buff(THD *thd, Item *arg);
unknown's avatar
unknown committed
1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549
  bool cmp(void);
  ~Item_str_buff();				// Deallocate String:s
};


class Item_real_buff :public Item_buff
{
  Item *item;
  double value;
public:
  Item_real_buff(Item *item_par) :item(item_par),value(0.0) {}
  bool cmp(void);
};

class Item_int_buff :public Item_buff
{
  Item *item;
  longlong value;
public:
  Item_int_buff(Item *item_par) :item(item_par),value(0) {}
  bool cmp(void);
};


unknown's avatar
unknown committed
1550 1551 1552 1553 1554 1555 1556 1557 1558
class Item_decimal_buff :public Item_buff
{
  Item *item;
  my_decimal value;
public:
  Item_decimal_buff(Item *item_par);
  bool cmp(void);
};

unknown's avatar
unknown committed
1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573
class Item_field_buff :public Item_buff
{
  char *buff;
  Field *field;
  uint length;

public:
  Item_field_buff(Item_field *item)
  {
    field=item->field;
    buff= (char*) sql_calloc(length=field->pack_length());
  }
  bool cmp(void);
};

unknown's avatar
SCRUM  
unknown committed
1574 1575 1576 1577
class Item_default_value : public Item_field
{
public:
  Item *arg;
unknown's avatar
SCRUM  
unknown committed
1578 1579
  Item_default_value() :
    Item_field((const char *)NULL, (const char *)NULL, (const char *)NULL), arg(NULL) {}
unknown's avatar
unknown committed
1580
  Item_default_value(Item *a) :
unknown's avatar
SCRUM  
unknown committed
1581
    Item_field((const char *)NULL, (const char *)NULL, (const char *)NULL), arg(a) {}
unknown's avatar
SCRUM  
unknown committed
1582
  enum Type type() const { return DEFAULT_VALUE_ITEM; }
unknown's avatar
SCRUM  
unknown committed
1583 1584
  bool eq(const Item *item, bool binary_cmp) const;
  bool fix_fields(THD *, struct st_table_list *, Item **);
unknown's avatar
SCRUM  
unknown committed
1585
  void print(String *str);
1586
  int save_in_field(Field *field_arg, bool no_conversions);
unknown's avatar
SCRUM  
unknown committed
1587
  table_map used_tables() const { return (table_map)0L; }
unknown's avatar
unknown committed
1588 1589 1590 1591 1592 1593
  
  bool walk(Item_processor processor, byte *args)
  {
    return arg->walk(processor, args) ||
      (this->*processor)(args);
  }
1594

unknown's avatar
unknown committed
1595 1596 1597 1598 1599
  /* 
     This method like the walk method traverses the item tree, but
     at the same time it can replace some nodes in the tree
  */ 
  Item *transform(Item_transformer transformer, byte *args)
1600
  {
unknown's avatar
unknown committed
1601
    Item *new_item= arg->transform(transformer, args);
1602 1603 1604
    if (!new_item)
      return 0;
    arg= new_item;
unknown's avatar
unknown committed
1605
    return (this->*transformer)(args);
1606
  }
unknown's avatar
unknown committed
1607
};
unknown's avatar
unknown committed
1608

unknown's avatar
unknown committed
1609 1610 1611 1612 1613 1614 1615 1616 1617
class Item_insert_value : public Item_field
{
public:
  Item *arg;
  Item_insert_value(Item *a) :
    Item_field((const char *)NULL, (const char *)NULL, (const char *)NULL), arg(a) {}
  bool eq(const Item *item, bool binary_cmp) const;
  bool fix_fields(THD *, struct st_table_list *, Item **);
  void print(String *str);
1618
  int save_in_field(Field *field_arg, bool no_conversions)
unknown's avatar
unknown committed
1619
  {
1620
    return Item_field::save_in_field(field_arg, no_conversions);
unknown's avatar
unknown committed
1621 1622
  }
  table_map used_tables() const { return (table_map)0L; }
unknown's avatar
unknown committed
1623 1624 1625 1626 1627 1628

  bool walk(Item_processor processor, byte *args)
  {
    return arg->walk(processor, args) ||
	    (this->*processor)(args);
  }
unknown's avatar
unknown committed
1629 1630
};

1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651

/*
  We need this two enums here instead of sql_lex.h because
  at least one of them is used by Item_trigger_field interface.

  Time when trigger is invoked (i.e. before or after row actually
  inserted/updated/deleted).
*/
enum trg_action_time_type
{
  TRG_ACTION_BEFORE= 0, TRG_ACTION_AFTER= 1
};

/*
  Event on which trigger is invoked.
*/
enum trg_event_type
{
  TRG_EVENT_INSERT= 0 , TRG_EVENT_UPDATE= 1, TRG_EVENT_DELETE= 2
};

unknown's avatar
unknown committed
1652 1653
class Table_triggers_list;

1654 1655 1656 1657
/*
  Represents NEW/OLD version of field of row which is
  changed/read in trigger.

unknown's avatar
unknown committed
1658 1659 1660 1661 1662 1663
  Note: For this item main part of actual binding to Field object happens
        not during fix_fields() call (like for Item_field) but right after
        parsing of trigger definition, when table is opened, with special
        setup_field() call. On fix_fields() stage we simply choose one of
        two Field instances representing either OLD or NEW version of this
        field.
1664 1665 1666 1667 1668 1669 1670
*/
class Item_trigger_field : public Item_field
{
public:
  /* Is this item represents row from NEW or OLD row ? */
  enum row_version_type {OLD_ROW, NEW_ROW};
  row_version_type row_version;
1671 1672
  /* Next in list of all Item_trigger_field's in trigger */
  Item_trigger_field *next_trg_field;
unknown's avatar
unknown committed
1673 1674 1675 1676
  /* Index of the field in the TABLE::field array */
  uint field_idx;
  /* Pointer to Table_trigger_list object for table of this trigger */
  Table_triggers_list *triggers;
1677 1678 1679 1680

  Item_trigger_field(row_version_type row_ver_par,
                     const char *field_name_par):
    Item_field((const char *)NULL, (const char *)NULL, field_name_par),
unknown's avatar
unknown committed
1681
    row_version(row_ver_par), field_idx((uint)-1)
1682
  {}
unknown's avatar
unknown committed
1683
  void setup_field(THD *thd, TABLE *table);
1684 1685 1686 1687 1688 1689 1690 1691 1692
  enum Type type() const { return TRIGGER_FIELD_ITEM; }
  bool eq(const Item *item, bool binary_cmp) const;
  bool fix_fields(THD *, struct st_table_list *, Item **);
  void print(String *str);
  table_map used_tables() const { return (table_map)0L; }
  void cleanup();
};


1693 1694
class Item_cache: public Item
{
unknown's avatar
unknown committed
1695 1696
protected:
  Item *example;
1697
  table_map used_table_map;
1698
public:
unknown's avatar
unknown committed
1699
  Item_cache(): example(0), used_table_map(0) {fixed= 1; null_value= 1;}
1700 1701 1702

  void set_used_tables(table_map map) { used_table_map= map; }

unknown's avatar
unknown committed
1703
  virtual bool allocate(uint i) { return 0; }
1704
  virtual bool setup(Item *item)
1705
  {
1706 1707 1708 1709 1710 1711
    example= item;
    max_length= item->max_length;
    decimals= item->decimals;
    collation.set(item->collation);
    return 0;
  };
1712 1713
  virtual void store(Item *)= 0;
  enum Type type() const { return CACHE_ITEM; }
1714
  static Item_cache* get_cache(Item_result type);
1715
  table_map used_tables() const { return used_table_map; }
1716
  virtual void keep_array() {}
1717
  // to prevent drop fixed flag (no need parent cleanup call)
unknown's avatar
unknown committed
1718
  void cleanup() {}
unknown's avatar
unknown committed
1719
  void print(String *str);
1720 1721
};

unknown's avatar
unknown committed
1722

1723 1724
class Item_cache_int: public Item_cache
{
unknown's avatar
unknown committed
1725
protected:
1726 1727
  longlong value;
public:
1728
  Item_cache_int(): Item_cache(), value(0) {}
unknown's avatar
unknown committed
1729

unknown's avatar
unknown committed
1730
  void store(Item *item);
1731
  double val_real() { DBUG_ASSERT(fixed == 1); return (double) value; }
1732
  longlong val_int() { DBUG_ASSERT(fixed == 1); return value; }
unknown's avatar
unknown committed
1733 1734
  String* val_str(String *str);
  my_decimal *val_decimal(my_decimal *);
1735 1736 1737
  enum Item_result result_type() const { return INT_RESULT; }
};

unknown's avatar
unknown committed
1738

1739 1740 1741 1742
class Item_cache_real: public Item_cache
{
  double value;
public:
1743
  Item_cache_real(): Item_cache(), value(0) {}
1744

unknown's avatar
unknown committed
1745
  void store(Item *item);
1746
  double val_real() { DBUG_ASSERT(fixed == 1); return value; }
unknown's avatar
unknown committed
1747 1748 1749
  longlong val_int();
  String* val_str(String *str);
  my_decimal *val_decimal(my_decimal *);
1750 1751 1752
  enum Item_result result_type() const { return REAL_RESULT; }
};

unknown's avatar
unknown committed
1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769

class Item_cache_decimal: public Item_cache
{
protected:
  my_decimal decimal_value;
public:
  Item_cache_decimal(): Item_cache() {}

  void store(Item *item);
  double val_real();
  longlong val_int();
  String* val_str(String *str);
  my_decimal *val_decimal(my_decimal *);
  enum Item_result result_type() const { return DECIMAL_RESULT; }
};


1770 1771
class Item_cache_str: public Item_cache
{
unknown's avatar
unknown committed
1772
  char buffer[STRING_BUFFER_USUAL_SIZE];
1773
  String *value, value_buff;
1774
public:
1775
  Item_cache_str(): Item_cache(), value(0) { }
unknown's avatar
unknown committed
1776

1777
  void store(Item *item);
1778
  double val_real();
1779
  longlong val_int();
1780
  String* val_str(String *) { DBUG_ASSERT(fixed == 1); return value; }
unknown's avatar
unknown committed
1781
  my_decimal *val_decimal(my_decimal *);
1782 1783 1784 1785
  enum Item_result result_type() const { return STRING_RESULT; }
  CHARSET_INFO *charset() const { return value->charset(); };
};

unknown's avatar
unknown committed
1786 1787 1788
class Item_cache_row: public Item_cache
{
  Item_cache  **values;
unknown's avatar
unknown committed
1789
  uint item_count;
1790
  bool save_array;
unknown's avatar
unknown committed
1791
public:
1792 1793
  Item_cache_row()
    :Item_cache(), values(0), item_count(2), save_array(0) {}
unknown's avatar
unknown committed
1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810
  
  /*
    'allocate' used only in row transformer, to preallocate space for row 
    cache.
  */
  bool allocate(uint num);
  /*
    'setup' is needed only by row => it not called by simple row subselect
    (only by IN subselect (in subselect optimizer))
  */
  bool setup(Item *item);
  void store(Item *item);
  void illegal_method_call(const char *);
  void make_field(Send_field *)
  {
    illegal_method_call((const char*)"make_field");
  };
1811
  double val_real()
unknown's avatar
unknown committed
1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825
  {
    illegal_method_call((const char*)"val");
    return 0;
  };
  longlong val_int()
  {
    illegal_method_call((const char*)"val_int");
    return 0;
  };
  String *val_str(String *)
  {
    illegal_method_call((const char*)"val_str");
    return 0;
  };
unknown's avatar
unknown committed
1826 1827 1828 1829 1830 1831
  my_decimal *val_decimal(my_decimal *val)
  {
    illegal_method_call((const char*)"val_decimal");
    return 0;
  };

unknown's avatar
unknown committed
1832 1833
  enum Item_result result_type() const { return ROW_RESULT; }
  
unknown's avatar
unknown committed
1834
  uint cols() { return item_count; }
unknown's avatar
unknown committed
1835 1836 1837 1838 1839
  Item* el(uint i) { return values[i]; }
  Item** addr(uint i) { return (Item **) (values + i); }
  bool check_cols(uint c);
  bool null_inside();
  void bring_value();
1840
  void keep_array() { save_array= 1; }
unknown's avatar
unknown committed
1841 1842
  void cleanup()
  {
unknown's avatar
unknown committed
1843
    DBUG_ENTER("Item_cache_row::cleanup");
unknown's avatar
unknown committed
1844
    Item_cache::cleanup();
1845 1846 1847 1848
    if (save_array)
      bzero(values, item_count*sizeof(Item**));
    else
      values= 0;
unknown's avatar
unknown committed
1849
    DBUG_VOID_RETURN;
unknown's avatar
unknown committed
1850
  }
unknown's avatar
unknown committed
1851 1852
};

1853 1854

/*
1855 1856 1857 1858 1859
  Item_type_holder used to store type. name, length of Item for UNIONS &
  derived tables.

  Item_type_holder do not need cleanup() because its time of live limited by
  single SP/PS execution.
1860 1861 1862 1863
*/
class Item_type_holder: public Item
{
protected:
1864 1865 1866 1867
  TYPELIB *enum_set_typelib;
  enum_field_types fld_type;

  void get_full_info(Item *item);
unknown's avatar
unknown committed
1868 1869 1870

  /* It is used to count decimal precision in join_types */
  int prev_decimal_int_part;
1871
public:
1872
  Item_type_holder(THD*, Item*);
1873

1874 1875
  Item_result result_type() const;
  virtual enum_field_types field_type() const { return fld_type; };
1876
  enum Type type() const { return TYPE_HOLDER; }
1877
  double val_real();
1878
  longlong val_int();
unknown's avatar
unknown committed
1879
  my_decimal *val_decimal(my_decimal *);
1880
  String *val_str(String*);
1881 1882 1883 1884
  bool join_types(THD *thd, Item *);
  Field *make_field_by_type(TABLE *table);
  static uint32 display_length(Item *item);
  static enum_field_types get_real_type(Item *);
1885 1886
};

1887 1888 1889
class st_select_lex;
void mark_select_range_as_dependent(THD *thd,
                                    st_select_lex *last_select,
unknown's avatar
unknown committed
1890
                                    st_select_lex *current_sel,
1891 1892
                                    Field *found_field, Item *found_item,
                                    Item_ident *resolved_item);
1893

1894
extern Item_buff *new_Item_buff(THD *thd, Item *item);
unknown's avatar
unknown committed
1895
extern Item_result item_cmp_type(Item_result a,Item_result b);
1896
extern void resolve_const_item(THD *thd, Item **ref, Item *cmp_item);
unknown's avatar
unknown committed
1897
extern bool field_is_equal_to_item(Field *field,Item *item);