CAST(expr AS CHAR(10)) is now working

mysql-test/r/cast.result

@@ -42,6 +42,60 @@ t1	CREATE TABLE `t1` (
   `t` char(4) character set cp1251 NOT NULL default ''
 ) TYPE=MyISAM CHARSET=latin1
 drop table t1;
+select
+cast(_latin1'ab'  AS char)    as c1,
+cast(_latin1'a '  AS char)    as c2,
+cast(_latin1'abc' AS char(2)) as c3,
+cast(_latin1'a  ' AS char(2)) as c4,
+cast(_latin1'a'   AS char(2)) as c5;
+c1	c2	c3	c4	c5
+ab	a 	ab	a 	a
+create table t1 select
+cast(_latin1'ab'  AS char)    as c1,
+cast(_latin1'a '  AS char)    as c2,
+cast(_latin1'abc' AS char(2)) as c3,
+cast(_latin1'a  ' AS char(2)) as c4,
+cast(_latin1'a'   AS char(2)) as c5;
+select * from t1;
+c1	c2	c3	c4	c5
+ab	a	ab	a	a
+show create table t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` char(2) binary NOT NULL default '',
+  `c2` char(2) binary NOT NULL default '',
+  `c3` char(2) binary NOT NULL default '',
+  `c4` char(2) binary NOT NULL default '',
+  `c5` char(2) binary NOT NULL default ''
+) TYPE=MyISAM CHARSET=latin1
+drop table t1;
+select
+cast(_koi8r''  AS nchar)    as c1,
+cast(_koi8r' '  AS nchar)    as c2,
+cast(_koi8r'' AS nchar(2)) as c3,
+cast(_koi8r'  ' AS nchar(2)) as c4,
+cast(_koi8r''   AS nchar(2)) as c5;
+c1	c2	c3	c4	c5
+фг	ф 	фг	ф 	ф
+create table t1 select
+cast(_koi8r''  AS nchar)    as c1,
+cast(_koi8r' '  AS nchar)    as c2,
+cast(_koi8r'' AS nchar(2)) as c3,
+cast(_koi8r'  ' AS nchar(2)) as c4,
+cast(_koi8r''   AS nchar(2)) as c5;
+select * from t1;
+c1	c2	c3	c4	c5
+фг	ф	фг	ф	ф
+show create table t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `c1` char(2) character set utf8 NOT NULL default '',
+  `c2` char(2) character set utf8 NOT NULL default '',
+  `c3` char(2) character set utf8 NOT NULL default '',
+  `c4` char(2) character set utf8 NOT NULL default '',
+  `c5` char(2) character set utf8 NOT NULL default ''
+) TYPE=MyISAM CHARSET=latin1
+drop table t1;
 select cast("2001-1-1" as date) = "2001-01-01";
 cast("2001-1-1" as date) = "2001-01-01"
 1

mysql-test/t/cast.test

@@ -23,6 +23,47 @@ create table t1 select cast(_koi8r'
 show create table t1;
 drop table t1;
 
+#
+# CAST to CHAR with/without length
+#
+select
+  cast(_latin1'ab'  AS char)    as c1,
+  cast(_latin1'a '  AS char)    as c2,
+  cast(_latin1'abc' AS char(2)) as c3,
+  cast(_latin1'a  ' AS char(2)) as c4,
+  cast(_latin1'a'   AS char(2)) as c5;
+
+create table t1 select
+  cast(_latin1'ab'  AS char)    as c1,
+  cast(_latin1'a '  AS char)    as c2,
+  cast(_latin1'abc' AS char(2)) as c3,
+  cast(_latin1'a  ' AS char(2)) as c4,
+  cast(_latin1'a'   AS char(2)) as c5;
+select * from t1;
+show create table t1;
+drop table t1;
+
+#
+# CAST to NCHAR with/without length
+#
+select
+  cast(_koi8r''  AS nchar)    as c1,
+  cast(_koi8r' '  AS nchar)    as c2,
+  cast(_koi8r'' AS nchar(2)) as c3,
+  cast(_koi8r'  ' AS nchar(2)) as c4,
+  cast(_koi8r''   AS nchar(2)) as c5;
+
+create table t1 select
+  cast(_koi8r''  AS nchar)    as c1,
+  cast(_koi8r' '  AS nchar)    as c2,
+  cast(_koi8r'' AS nchar(2)) as c3,
+  cast(_koi8r'  ' AS nchar(2)) as c4,
+  cast(_koi8r''   AS nchar(2)) as c5;
+select * from t1;
+show create table t1;
+drop table t1;
+
+
 #
 # The following should be fixed in 4.1
 #

sql/item_create.cc

@@ -470,21 +470,21 @@ Item *create_load_file(Item* a)
 }
 
 
-Item *create_func_cast(Item *a, Cast_target cast_type, CHARSET_INFO *cs)
+Item *create_func_cast(Item *a, Cast_target cast_type, int len, CHARSET_INFO *cs)
 {
   Item *res;
   LINT_INIT(res);
   switch (cast_type) {
   case ITEM_CAST_BINARY: 	res= new Item_func_binary(a); break;
-  case ITEM_CAST_CHAR:
-    res= (cs == NULL) ? (Item*) new Item_char_typecast(a) : 
-			(Item*) new Item_func_conv_charset(a,cs);
-    break;
   case ITEM_CAST_SIGNED_INT:	res= new Item_func_signed(a); break;
   case ITEM_CAST_UNSIGNED_INT:  res= new Item_func_unsigned(a); break;
   case ITEM_CAST_DATE:		res= new Item_date_typecast(a); break;
   case ITEM_CAST_TIME:		res= new Item_time_typecast(a); break;
   case ITEM_CAST_DATETIME:	res= new Item_datetime_typecast(a); break;
+  case ITEM_CAST_CHAR:
+    res= new Item_char_typecast(a, len, cs ? cs : 
+				current_thd->variables.collation_connection);
+    break;
   }
   return res;
 }

sql/item_create.h

@@ -28,7 +28,7 @@ Item *create_func_bit_length(Item* a);
 Item *create_func_coercibility(Item* a);
 Item *create_func_ceiling(Item* a);
 Item *create_func_char_length(Item* a);
-Item *create_func_cast(Item *a, Cast_target cast_type, CHARSET_INFO *cs);
+Item *create_func_cast(Item *a, Cast_target cast_type, int len, CHARSET_INFO *cs);
 Item *create_func_connection_id(void);
 Item *create_func_conv(Item* a, Item *b, Item *c);
 Item *create_func_cos(Item* a);

sql/item_timefunc.cc

@@ -1474,6 +1474,59 @@ void Item_typecast::print(String *str)
   str->append(')');
 }
 
+String *Item_char_typecast::val_str(String *str)
+{
+  String *res, *res1;
+  uint32 length;
+
+  if (!charset_conversion && !(res= args[0]->val_str(str)))
+  {
+    null_value= 1;
+    return 0;
+  }
+  else
+  {
+    // Convert character set if differ
+    if (!(res1= args[0]->val_str(&tmp_value)) ||
+	str->copy(res1->ptr(), res1->length(),res1->charset(), cast_cs))
+    {
+      null_value= 1;
+      return 0;
+    }
+    res= str;
+  }
+  
+  /*
+     Cut the tail if cast with length
+     and the result is longer than cast length, e.g.
+     CAST('string' AS CHAR(1))
+  */
+  if (cast_length >= 0 && 
+      (res->length() > (length= (uint32) res->charpos(cast_length))))
+  {						// Safe even if const arg
+    if (!res->alloced_length())
+    {						// Don't change const str
+      str_value= *res;				// Not malloced string
+      res= &str_value;
+    }
+    res->length((uint) length);
+  } 
+  null_value= 0;
+  return res;
+}
+
+void Item_char_typecast::fix_length_and_dec()
+{
+  uint32 char_length;
+  charset_conversion= !my_charset_same(args[0]->collation.collation, cast_cs) &&
+		      args[0]->collation.collation != &my_charset_bin &&
+		      cast_cs != &my_charset_bin;
+  collation.set(cast_cs, DERIVATION_IMPLICIT);
+  char_length= (cast_length >= 0) ? cast_length : 
+	       args[0]->max_length/args[0]->collation.collation->mbmaxlen;
+  max_length= char_length * cast_cs->mbmaxlen;
+}
+
 String *Item_datetime_typecast::val_str(String *str)
 {
   TIME ltime;

sql/item_timefunc.h

@@ -614,13 +614,15 @@ public:
 
 class Item_char_typecast :public Item_typecast
 {
-public:
-  Item_char_typecast(Item *a) :Item_typecast(a) {}
-  void fix_length_and_dec()
-  {
-    collation.set(default_charset());
-    max_length=args[0]->max_length;
-  }
+  int cast_length;
+  CHARSET_INFO *cast_cs;
+  bool charset_conversion;
+  String tmp_value;
+public:
+  Item_char_typecast(Item *a, int length_arg, CHARSET_INFO *cs_arg)
+    :Item_typecast(a), cast_length(length_arg), cast_cs(cs_arg) {}
+  String *val_str(String *a);
+  void fix_length_and_dec();
 };
 
 

sql/sql_yacc.yy

@@ -642,7 +642,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b,int *yystacksize);
 
 %type <ha_rkey_mode> handler_rkey_mode
 
-%type <cast_type> cast_type
+%type <cast_type> cast_type cast_type_finalize
 
 %type <udf_type> udf_func_type
 
@@ -2355,11 +2355,19 @@ simple_expr:
 					    6, &my_charset_latin1));
 	  }
 	| CAST_SYM '(' expr AS cast_type ')'
-	  { $$= create_func_cast($3, $5, Lex->charset); }
+	  { 
+	    $$= create_func_cast($3, $5, 
+				 Lex->length ? atoi(Lex->length) : -1,
+				 Lex->charset); 
+	  }
 	| CASE_SYM opt_expr WHEN_SYM when_list opt_else END
 	  { $$= new Item_func_case(* $4, $2, $5 ); }
 	| CONVERT_SYM '(' expr ',' cast_type ')'
-	  { $$= create_func_cast($3, $5, Lex->charset); }
+	  {
+	    $$= create_func_cast($3, $5,
+				 Lex->length ? atoi(Lex->length) : -1,
+				 Lex->charset);
+	  }
 	| CONVERT_SYM '(' expr USING charset_name ')'
 	  { $$= new Item_func_conv_charset($3,$5); }
 	| CONVERT_SYM '(' expr ',' expr ',' expr ')'
@@ -2800,16 +2808,25 @@ in_sum_expr:
 	  $$= $3;
 	};
 
+cast_type_init:
+	{ Lex->charset= NULL; Lex->length= (char*)0; }
+	;
+
+cast_type_finalize:
+	BINARY			{ $$=ITEM_CAST_BINARY; }
+	| CHAR_SYM opt_len opt_binary	{ $$=ITEM_CAST_CHAR; }
+	| NCHAR_SYM opt_len	{ $$=ITEM_CAST_CHAR; Lex->charset= national_charset_info; }
+	| SIGNED_SYM		{ $$=ITEM_CAST_SIGNED_INT; }
+	| SIGNED_SYM INT_SYM	{ $$=ITEM_CAST_SIGNED_INT; }
+	| UNSIGNED		{ $$=ITEM_CAST_UNSIGNED_INT; }
+	| UNSIGNED INT_SYM	{ $$=ITEM_CAST_UNSIGNED_INT; }
+	| DATE_SYM		{ $$=ITEM_CAST_DATE; }
+	| TIME_SYM		{ $$=ITEM_CAST_TIME; }
+	| DATETIME		{ $$=ITEM_CAST_DATETIME; }
+	;
+
 cast_type:
-	BINARY			{ $$=ITEM_CAST_BINARY; Lex->charset= NULL; }
-	| CHAR_SYM opt_binary	{ $$=ITEM_CAST_CHAR; }
-	| SIGNED_SYM		{ $$=ITEM_CAST_SIGNED_INT; Lex->charset= NULL; }
-	| SIGNED_SYM INT_SYM	{ $$=ITEM_CAST_SIGNED_INT; Lex->charset= NULL; }
-	| UNSIGNED		{ $$=ITEM_CAST_UNSIGNED_INT; Lex->charset= NULL; }
-	| UNSIGNED INT_SYM	{ $$=ITEM_CAST_UNSIGNED_INT; Lex->charset= NULL; }
-	| DATE_SYM		{ $$=ITEM_CAST_DATE; Lex->charset= NULL; }
-	| TIME_SYM		{ $$=ITEM_CAST_TIME; Lex->charset= NULL; }
-	| DATETIME		{ $$=ITEM_CAST_DATETIME; Lex->charset= NULL; }
+	cast_type_init cast_type_finalize { $$= $2; }
 	;
 
 expr_list: