WL#962: Added simple, read-only, non-scrolling, asensitive cursors in SPs, using the

(updated) Protocol_cursor class.
Also did some bug fixes.

Docs/sp-imp-spec.txt

@@ -11,7 +11,7 @@
   which dispatches on the command code (in Lex) to the corresponding code for
   executing that particular query.
 
-  There are thre structures involved in the execution of a query which are of
+  There are three structures involved in the execution of a query which are of
   interest to the stored procedure implementation:
 
   - Lex (mentioned above) is the "compiled" query, that is the output from
@@ -186,7 +186,7 @@
     stored in the table mysql.proc with the name and type as the key, the
     type being one of the enum ("procedure","function").
 
-    A PROCEDURE is just stored int the mysql.proc table. A FUNCTION has an
+    A PROCEDURE is just stored in the mysql.proc table. A FUNCTION has an
     additional requirement. They will be called in expressions with the same
     syntax as UDFs, so UDFs and stored FUNCTIONs share the namespace. Thus,
     we must make sure that we do not have UDFs and FUNCTIONs with the same
@@ -293,7 +293,7 @@
     So, stored functions must be handled in a simpilar way, and as a
     consequence, UDFs and functions must not have the same name.
 
-    - Detecting and parsing a FUNCTION invokation
+    - Detecting and parsing a FUNCTION invocation
 
       The existance of UDFs are checked during the lexical analysis (in
       sql_lex.cc:find_keyword()). This has the drawback that they must
@@ -319,7 +319,7 @@
       "on-the-fly" during the execution of *another* statement.
       This makes things a lot more complicated compared to CALL:
       - We can't read and parse the FUNCTION from the mysql.proc table at the
-        point of invokation; the server requires that all tables used are
+        point of invocation; the server requires that all tables used are
         opened and locked at the beginning of the query execution.
       One "obvious" solution would be to simply push "mysql.proc" to the list
       of tables used by the query, but this implies a "join" with this table
@@ -478,6 +478,67 @@
        7    sp_instr_hpop(2)
 
 
+  - Cursors
+
+    For stored procedures to be really useful, you want to have cursors.
+    MySQL doesn't yet have "real" cursor support (with API and ODBC support,
+    allowing updating, arbitrary scrolling, etc), but a simple asensitive,
+    non-scrolling, read-only cursor can be implemented in SPs using the
+    class Protocol_cursor.
+    This class intecepts the creation and sending of results sets and instead
+    stores it in-memory, as MYSQL_FIELDS and MYSQL_ROWS (as in the client API).
+
+    To support this, we need the usual name binding support in sp_pcontext
+    (similar to variables and conditions) to keep track on declared cursor
+    names, and a corresponding run-time mechanism in sp_rcontext.
+    Cursors are lexically scoped like everything with a body or BEGIN/END
+    block, so they are pushed and poped as usual (see conditions and variables
+    above).
+    The basic operations on a cursor are OPEN, FETCH and CLOSE, which will
+    each have a corresponding instruction. In addition, we need instructions
+    to push a new cursor (this will encapsulate the LEX of the SELECT statement
+    of the cursor), and a pop instruction:
+    - sp_instr_cpush
+      Push a cursor to the sp_rcontext. This instruction contains the LEX
+      for the select statement
+    - sp_instr_cpop
+      Pop a number of cursors from the sp_rcontext.
+    - sp_instr_copen
+      Open a cursor: This will execute the select and get the result set
+      in a sepeate memroot.
+    - sp_instr_cfetch
+      Fetch the next row from the in-memory result set. The instruction
+      contains a list of the variables (frame offsets) to set.
+    - sp_instr_cclose
+      Free the result set.
+
+    A cursor is a separate class, sp_cursor (defined in sp_rcontex.h) which
+    encapsulates the basic operations used by the above instructions.
+    This class contains the LEX, Protocol_cursor object, and its memroot,
+    as well as the cursor's current state.
+    Compiling and executing is fairly straight-forward. sp_instr_copen is
+    a subclass of sp_instr_stmt and uses its mechanism to execute a
+    substatement.
+
+    - Example:
+
+      begin
+        declare x int;
+        declare c cursor for select a from t1;
+
+        open c;
+        fetch c into x;
+        close c;
+      end
+
+      Pos.  Instruction
+       0    sp_instr_cpush('select a from ...')
+       1    sp_instr_copen(0)                   # The 0'th cursor
+       2    sp_instr_cfetch(0)                  # Contains the variable list
+       3    sp_instr_cclose(0)
+       4    sp_instr_cpop(1)
+    
+
   - Class and function APIs
     This is an outline of the key types. Some types and other details
     in the actual files have been omitted for readability.
@@ -569,6 +630,18 @@
 
         // Returns the handler count
         uint handlers();
+
+	// Push a cursor
+        void push_cursor(LEX_STRING *name);
+
+	// Find a cursor
+	my_bool find_cursor(LEX_STRING *name, uint *poff);
+
+	// Pop 'num' cursors
+	void pop_cursor(uint num);
+
+	// Return the number of cursors
+	uint cursors();
       }
 
 
@@ -589,8 +662,9 @@
 
     class sp_rcontext
     {
-      // 'fsize' is the max size of the context, 'hmax' the number of handlers
-      sp_rcontext(uint fsize, uint hmax);
+      // 'fsize' is the max size of the context, 'hmax' the number of handlers,
+      // 'cmax' the number of cursors
+      sp_rcontext(uint fsize, uint hmax, , uint cmax);
 
       // Push value (parameter) 'i' to the frame
       void push_item(Item *i);
@@ -645,6 +719,18 @@
       // Restore saved variables from to frame index 'fp' and up.
       void restore_variables(uint fp);
 
+      // Push a cursor for the statement (lex)
+      void push_cursor(LEX *lex);
+
+      // Pop 'count' cursors
+      void pop_cursors(uint count);
+
+      // Pop all cursors
+      void pop_all_cursors();
+
+      // Get the 'i'th cursor
+      sp_cursor *get_cursor(uint i);
+
     }
 
 
@@ -709,6 +795,7 @@
                          bool suid, char *comment, uint commentlen);
       }
 
+
     - Instructions
 
       - The base class:
@@ -816,6 +903,55 @@
           int execute(THD *thd, uint *nextp);
         }
 
+      - Push a CURSOR
+        class sp_instr_cpush : public sp_instr_stmt
+	{
+          // Push a cursor for statement 'lex'
+	  sp_instr_cpush(uint ip, LEX *lex)
+
+	  int execute(THD *thd, uint *nextp);
+        }
+
+      - Pop CURSORs
+        class sp_instr_cpop : public sp_instr_stmt
+	{
+          // Pop 'count' cursors
+	  sp_instr_cpop(uint ip, uint count)
+
+	  int execute(THD *thd, uint *nextp);
+        }
+
+      - Open a CURSOR
+        class sp_instr_copen : public sp_instr_stmt
+	{
+          // Open the 'c'th cursor
+	  sp_instr_copen(uint ip, uint c);
+
+	  int execute(THD *thd, uint *nextp);
+        }
+
+      - Close a CURSOR
+        class sp_instr_cclose : public sp_instr
+	{
+          // Close the 'c'th cursor
+	  sp_instr_cclose(uint ip, uint c);
+
+	  int execute(THD *thd, uint *nextp);
+        }
+
+      - Fetch a row with CURSOR
+        class sp_instr_cfetch : public sp_instr
+	{
+          // Fetch next with the 'c'th cursor
+	  sp_instr_cfetch(uint ip, uint c);
+
+	  int execute(THD *thd, uint *nextp);
+
+	  // Add a target variable for the fetch
+	  void add_to_varlist(struct sp_pvar *var);
+        }
+
+	
     - Utility functions: sp.h
 
       #define SP_OK                 0

Docs/sp-implemented.txt

@@ -8,8 +8,7 @@ Summary of Not Yet Implemented:
   - Access control
   - Routine characteristics (mostly used for external languages)
   - SQL-99 COMMIT (related to BEGIN/END)
-  - DECLARE CURSOR ...
-  - FOR-loops (as it requires cursors)
+  - FOR-loops
   - CASCADE/RESTRICT for ALTER and DROP
   - ALTER/DROP METHOD (as it implies User Defined Types)
   - SIGNAL and RESIGNAL, and UNDO handlers
@@ -25,6 +24,7 @@ Summary of what's implemented:
   - "Non-query" FUNCTIONs only
   - Prepared SP caching
   - CONDITIONs and HANDLERs
+  - Simple read-only CURSORs.
 
 List of what's implemented:
 
@@ -86,6 +86,11 @@ List of what's implemented:
       The semantics of CONDITIONs is expanded to allow catching MySQL error
       codes as well. UNDO handlers are not implemented (since we don't have
       SQL-99 style transaction control yet).
+    - Simple read-only CURSORs are implemented, but not yet any of the
+      optional arguments to DECLARE (SCROLL, SENSITIVE, etc) or FETCH
+      (NEXT, PRIOR, etc). Cursors are ASENSITIVE, READ-ONLY, non-SCROLLing.
+      (The additional syntax will be added for completeness, but for the
+       most part unsupported with the current underlying cursor mechanism.)
 
 Closed questions:
 

include/mysqld_error.h

@@ -314,4 +314,12 @@
 #define ER_SP_COND_MISMATCH 1295
 #define ER_SP_NORETURN 1296
 #define ER_SP_NORETURNEND 1297
-#define ER_ERROR_MESSAGES 298
+#define ER_SP_BAD_CURSOR_QUERY 1298
+#define ER_SP_BAD_CURSOR_SELECT 1299
+#define ER_SP_CURSOR_MISMATCH 1300
+#define ER_SP_CURSOR_ALREADY_OPEN 1301
+#define ER_SP_CURSOR_NOT_OPEN 1302
+#define ER_SP_UNDECLARED_VAR 1303
+#define ER_SP_WRONG_NO_OF_FETCH_ARGS 1304
+#define ER_SP_FETCH_NO_DATA 1305
+#define ER_ERROR_MESSAGES 306

libmysqld/Makefile.am

@@ -56,7 +56,7 @@ sqlsources = derror.cc field.cc field_conv.cc filesort.cc \
 	sql_string.cc sql_table.cc sql_test.cc sql_udf.cc \
 	sql_update.cc sql_yacc.cc table.cc thr_malloc.cc time.cc \
 	unireg.cc uniques.cc stacktrace.c sql_union.cc hash_filo.cc \
-	spatial.cc gstream.cc sql_help.cc \
+	spatial.cc gstream.cc sql_help.cc protocol_cursor.cc \
 	sp_head.cc sp_pcontext.cc sp.cc sp_cache.cc sp_rcontext.cc
 
 libmysqld_int_a_SOURCES= $(libmysqld_sources) $(libmysqlsources) $(sqlsources)

mysql-test/r/sp-error.result

@@ -138,3 +138,85 @@ end;
 select f(10);
 ERROR HY000: FUNCTION f ended without RETURN
 drop function f;
+create procedure p()
+begin
+declare c cursor for insert into test.t1 values ("foo", 42);
+open c;
+close c;
+end;
+ERROR HY000: Cursor statement must be a SELECT
+create procedure p()
+begin
+declare x int;
+declare c cursor for select * into x from test.t limit 1;
+open c;
+close c;
+end;
+ERROR HY000: Cursor SELECT must not have INTO
+create procedure p()
+begin
+declare c cursor for select * from test.t;
+open cc;
+close c;
+end;
+ERROR HY000: Undefined CURSOR: cc
+drop table if exists t1;
+create table t1 (val int);
+create procedure p()
+begin
+declare c cursor for select * from test.t1;
+open c;
+open c;
+close c;
+end;
+call p();
+ERROR HY000: Cursor is already open
+drop procedure p;
+create procedure p()
+begin
+declare c cursor for select * from test.t1;
+open c;
+close c;
+close c;
+end;
+call p();
+ERROR HY000: Cursor is not open
+drop procedure p;
+drop table t1;
+drop table if exists t1;
+create table t1 (val int, x float);
+insert into t1 values (42, 3.1), (19, 1.2);
+create procedure p()
+begin
+declare c cursor for select * from t1;
+declare x int;
+open c;
+fetch c into x, y;
+close c;
+end;
+ERROR HY000: Undeclared variable: y
+create procedure p()
+begin
+declare c cursor for select * from t1;
+declare x int;
+open c;
+fetch c into x;
+close c;
+end;
+call p();
+ERROR HY000: Wrong number of FETCH variables
+drop procedure p;
+create procedure p()
+begin
+declare c cursor for select * from t1;
+declare x int;
+declare y float;
+declare z int;
+open c;
+fetch c into x, y, z;
+close c;
+end;
+call p();
+ERROR HY000: Wrong number of FETCH variables
+drop procedure p;
+drop table t1;

mysql-test/r/sp.result

@@ -500,6 +500,33 @@ id	data
 hndlr3	13
 delete from t1;
 drop procedure hndlr3;
+create procedure cur1()
+begin
+declare done int default 0;
+declare continue handler for 1305 set done = 1;
+declare c cursor for select * from test.t2;
+declare a char(16);
+declare b int;
+declare c double;
+open c;
+repeat
+fetch c into a, b, c;
+if not done then
+insert into test.t1 values (a, b+c);
+end if;
+until done end repeat;
+close c;
+end;
+insert into t2 values ("foo", 42, -1.9), ("bar", 3, 12.1), ("zap", 666, -3.14);
+call cur1();
+select * from t1;
+id	data
+foo	40
+bar	15
+zap	663
+delete from t1;
+delete from t2;
+drop procedure cur1;
 create procedure bug822(a_id char(16), a_data int)
 begin
 declare n int;

mysql-test/t/sp-error.test

@@ -194,4 +194,110 @@ select f(10)|
 
 drop function f|
 
+--error 1298
+create procedure p()
+begin
+  declare c cursor for insert into test.t1 values ("foo", 42);
+
+  open c;
+  close c;
+end|
+
+--error 1299
+create procedure p()
+begin
+  declare x int;
+  declare c cursor for select * into x from test.t limit 1;
+
+  open c;
+  close c;
+end|
+
+--error 1300
+create procedure p()
+begin
+  declare c cursor for select * from test.t;
+
+  open cc;
+  close c;
+end|
+
+--disable_warnings
+drop table if exists t1|
+--enable_warnings
+create table t1 (val int)|
+
+create procedure p()
+begin
+  declare c cursor for select * from test.t1;
+
+  open c;
+  open c;
+  close c;
+end|
+--error 1301
+call p()|
+drop procedure p|
+
+create procedure p()
+begin
+  declare c cursor for select * from test.t1;
+
+  open c;
+  close c;
+  close c;
+end|
+--error 1302
+call p()|
+drop procedure p|
+
+drop table t1|
+
+--disable_warnings
+drop table if exists t1|
+--enable_warnings
+create table t1 (val int, x float)|
+insert into t1 values (42, 3.1), (19, 1.2)|
+
+--error 1303
+create procedure p()
+begin
+  declare c cursor for select * from t1;
+  declare x int;
+
+  open c;
+  fetch c into x, y;
+  close c;
+end|
+
+create procedure p()
+begin
+  declare c cursor for select * from t1;
+  declare x int;
+
+  open c;
+  fetch c into x;
+  close c;
+end|
+--error 1304
+call p()|
+drop procedure p|
+
+create procedure p()
+begin
+  declare c cursor for select * from t1;
+  declare x int;
+  declare y float;
+  declare z int;
+
+  open c;
+  fetch c into x, y, z;
+  close c;
+end|
+--error 1304
+call p()|
+drop procedure p|
+
+drop table t1|
+
 delimiter ;|

mysql-test/t/sp.test

@@ -588,7 +588,38 @@ select * from t1|
 delete from t1|
 drop procedure hndlr3|
 
+#
+# Cursors
+#
+create procedure cur1()
+begin
+  declare done int default 0;
+  declare continue handler for 1305 set done = 1;
+  declare c cursor for select * from test.t2;
+  declare a char(16);
+  declare b int;
+  declare c double;
+
+  open c;
+  repeat
+    fetch c into a, b, c;
+    if not done then
+       insert into test.t1 values (a, b+c);
+    end if;
+  until done end repeat;
+  close c;
+end|
 
+insert into t2 values ("foo", 42, -1.9), ("bar", 3, 12.1), ("zap", 666, -3.14)|
+call cur1()|
+select * from t1|
+delete from t1|
+delete from t2|
+drop procedure cur1|
+
+#
+# BUG#822
+#
 create procedure bug822(a_id char(16), a_data int)
 begin
   declare n int;

sql/protocol.cc

@@ -1145,12 +1145,3 @@ bool Protocol_prep::store_time(TIME *tm)
   buff[0]=(char) length;			// Length is stored first
   return packet->append(buff, length+1, PACKET_BUFFET_EXTRA_ALLOC);
 }
-
-#ifdef EMBEDDED_LIBRARY
-/* Should be removed when we define the Protocol_cursor's future */
-bool Protocol_cursor::write()
-{
-  return Protocol_simple::write();
-}
-#endif
-

sql/protocol.h

@@ -47,17 +47,13 @@ class Protocol
   Protocol(THD *thd) { init(thd); }
   virtual ~Protocol() {}
   void init(THD* thd);
-  bool send_fields(List<Item> *list, uint flag);
+  virtual bool send_fields(List<Item> *list, uint flag);
   bool send_records_num(List<Item> *list, ulonglong records);
   bool store(I_List<i_string> *str_list);
   bool store(const char *from, CHARSET_INFO *cs);
   String *storage_packet() { return packet; }
   inline void free() { packet->free(); }
-#ifndef EMBEDDED_LIBRARY
-  bool write();
-#else
   virtual bool write();
-#endif
   inline  bool store(uint32 from)
   { return store_long((longlong) from); }
   inline  bool store(longlong from)
@@ -158,6 +154,7 @@ class Protocol_cursor :public Protocol_simple
   Protocol_cursor(THD *thd, MEM_ROOT *ini_alloc) :Protocol_simple(thd), alloc(ini_alloc) {}
   bool prepare_for_send(List<Item> *item_list) 
   {
+    row_count= 0;
     fields= NULL;
     data= NULL;
     prev_record= &data;
@@ -165,6 +162,7 @@ class Protocol_cursor :public Protocol_simple
   }
   bool send_fields(List<Item> *list, uint flag);
   bool write();
+  uint get_field_count() { return field_count; }
 };
 
 void send_warning(THD *thd, uint sql_errno, const char *err=0);

sql/protocol_cursor.cc

@@ -51,6 +51,7 @@ bool Protocol_cursor::send_fields(List<Item> *list, uint flag)
     client_field->name=   strdup_root(alloc, server_field.col_name);
     client_field->org_table= strdup_root(alloc, server_field.org_table_name);
     client_field->org_name=  strdup_root(alloc, server_field.org_col_name);
+    client_field->catalog= strdup_root(alloc, "");
     client_field->length= server_field.length;
     client_field->type=   server_field.type;
     client_field->flags= server_field.flags;
@@ -60,6 +61,7 @@ bool Protocol_cursor::send_fields(List<Item> *list, uint flag)
     client_field->name_length=		strlen(client_field->name);
     client_field->org_name_length=	strlen(client_field->org_name);
     client_field->org_table_length=	strlen(client_field->org_table);
+    client_field->catalog_length=       0;
     client_field->charsetnr=		server_field.charsetnr;
     
     if (INTERNAL_NUM_FIELD(client_field))
@@ -100,17 +102,17 @@ bool Protocol_cursor::write()
   byte *to;
 
   new_record= (MYSQL_ROWS *)alloc_root(alloc, 
-       sizeof(MYSQL_ROWS) + (field_count + 1)*sizeof(char *) + packet->length());
+    sizeof(MYSQL_ROWS) + (field_count + 1)*sizeof(char *) + packet->length());
   if (!new_record)
     goto err;
   data= (byte **)(new_record + 1);
   new_record->data= (char **)data;
 
-  to= (byte *)(fields + field_count + 1);
+  to= (byte *)data + (field_count + 1)*sizeof(char *);
 
   for (; cur_field < fields_end; ++cur_field, ++data)
   {
-    if ((len=net_field_length((uchar **)&cp)))
+    if ((len= net_field_length((uchar **)&cp)) == 0)
     {
       *data= 0;
     }
@@ -121,6 +123,7 @@ bool Protocol_cursor::write()
 // TODO error signal      send_error(thd, CR_MALFORMED_PACKET);
 	return TRUE;
       }
+      *data= to;
       memcpy(to,(char*) cp,len);
       to[len]=0;
       to+=len+1;
@@ -129,6 +132,7 @@ bool Protocol_cursor::write()
 	cur_field->max_length=len;
     }
   }
+  *data= 0;
 
   *prev_record= new_record;
   prev_record= &new_record->next;
@@ -139,5 +143,3 @@ bool Protocol_cursor::write()
 // TODO error signal      send_error(thd, ER_OUT_OF_RESOURCES);
   return TRUE;
 }
-
-

sql/share/czech/errmsg.txt

@@ -310,3 +310,11 @@ character-set=latin2
 "Undefined CONDITION: %s"
 "No RETURN found in FUNCTION %s"
 "FUNCTION %s ended without RETURN"
+"Cursor statement must be a SELECT"
+"Cursor SELECT must not have INTO"
+"Undefined CURSOR: %s"
+"Cursor is already open"
+"Cursor is not open"
+"Undeclared variable: %s"
+"Wrong number of FETCH variables"
+"No data to FETCH"

sql/share/danish/errmsg.txt

@@ -304,3 +304,11 @@ character-set=latin1
 "Undefined CONDITION: %s"
 "No RETURN found in FUNCTION %s"
 "FUNCTION %s ended without RETURN"
+"Cursor statement must be a SELECT"
+"Cursor SELECT must not have INTO"
+"Undefined CURSOR: %s"
+"Cursor is already open"
+"Cursor is not open"
+"Undeclared variable: %s"
+"Wrong number of FETCH variables"
+"No data to FETCH"

sql/share/dutch/errmsg.txt

@@ -312,3 +312,11 @@ character-set=latin1
 "Undefined CONDITION: %s"
 "No RETURN found in FUNCTION %s"
 "FUNCTION %s ended without RETURN"
+"Cursor statement must be a SELECT"
+"Cursor SELECT must not have INTO"
+"Undefined CURSOR: %s"
+"Cursor is already open"
+"Cursor is not open"
+"Undeclared variable: %s"
+"Wrong number of FETCH variables"
+"No data to FETCH"

sql/share/english/errmsg.txt

@@ -301,3 +301,11 @@ character-set=latin1
 "Undefined CONDITION: %s"
 "No RETURN found in FUNCTION %s"
 "FUNCTION %s ended without RETURN"
+"Cursor statement must be a SELECT"
+"Cursor SELECT must not have INTO"
+"Undefined CURSOR: %s"
+"Cursor is already open"
+"Cursor is not open"
+"Undeclared variable: %s"
+"Wrong number of FETCH variables"
+"No data to FETCH"

sql/share/estonian/errmsg.txt

@@ -306,3 +306,11 @@ character-set=latin7
 "Undefined CONDITION: %s"
 "No RETURN found in FUNCTION %s"
 "FUNCTION %s ended without RETURN"
+"Cursor statement must be a SELECT"
+"Cursor SELECT must not have INTO"
+"Undefined CURSOR: %s"
+"Cursor is already open"
+"Cursor is not open"
+"Undeclared variable: %s"
+"Wrong number of FETCH variables"
+"No data to FETCH"

sql/share/french/errmsg.txt

@@ -301,3 +301,11 @@ character-set=latin1
 "Undefined CONDITION: %s"
 "No RETURN found in FUNCTION %s"
 "FUNCTION %s ended without RETURN"
+"Cursor statement must be a SELECT"
+"Cursor SELECT must not have INTO"
+"Undefined CURSOR: %s"
+"Cursor is already open"
+"Cursor is not open"
+"Undeclared variable: %s"
+"Wrong number of FETCH variables"
+"No data to FETCH"

sql/share/german/errmsg.txt

@@ -310,3 +310,11 @@ character-set=latin1
 "Undefined CONDITION: %s"
 "No RETURN found in FUNCTION %s"
 "FUNCTION %s ended without RETURN"
+"Cursor statement must be a SELECT"
+"Cursor SELECT must not have INTO"
+"Undefined CURSOR: %s"
+"Cursor is already open"
+"Cursor is not open"
+"Undeclared variable: %s"
+"Wrong number of FETCH variables"
+"No data to FETCH"

sql/share/greek/errmsg.txt

@@ -301,3 +301,11 @@ character-set=greek
 "Undefined CONDITION: %s"
 "No RETURN found in FUNCTION %s"
 "FUNCTION %s ended without RETURN"
+"Cursor statement must be a SELECT"
+"Cursor SELECT must not have INTO"
+"Undefined CURSOR: %s"
+"Cursor is already open"
+"Cursor is not open"
+"Undeclared variable: %s"
+"Wrong number of FETCH variables"
+"No data to FETCH"

sql/share/hungarian/errmsg.txt

@@ -303,3 +303,11 @@ character-set=latin2
 "Undefined CONDITION: %s"
 "No RETURN found in FUNCTION %s"
 "FUNCTION %s ended without RETURN"
+"Cursor statement must be a SELECT"
+"Cursor SELECT must not have INTO"
+"Undefined CURSOR: %s"
+"Cursor is already open"
+"Cursor is not open"
+"Undeclared variable: %s"
+"Wrong number of FETCH variables"
+"No data to FETCH"

sql/share/italian/errmsg.txt

@@ -301,3 +301,11 @@ character-set=latin1
 "Undefined CONDITION: %s"
 "No RETURN found in FUNCTION %s"
 "FUNCTION %s ended without RETURN"
+"Cursor statement must be a SELECT"
+"Cursor SELECT must not have INTO"
+"Undefined CURSOR: %s"
+"Cursor is already open"
+"Cursor is not open"
+"Undeclared variable: %s"
+"Wrong number of FETCH variables"
+"No data to FETCH"

sql/share/japanese/errmsg.txt

@@ -303,3 +303,11 @@ character-set=ujis
 "Undefined CONDITION: %s"
 "No RETURN found in FUNCTION %s"
 "FUNCTION %s ended without RETURN"
+"Cursor statement must be a SELECT"
+"Cursor SELECT must not have INTO"
+"Undefined CURSOR: %s"
+"Cursor is already open"
+"Cursor is not open"
+"Undeclared variable: %s"
+"Wrong number of FETCH variables"
+"No data to FETCH"

sql/share/korean/errmsg.txt

@@ -301,3 +301,11 @@ character-set=euckr
 "Undefined CONDITION: %s"
 "No RETURN found in FUNCTION %s"
 "FUNCTION %s ended without RETURN"
+"Cursor statement must be a SELECT"
+"Cursor SELECT must not have INTO"
+"Undefined CURSOR: %s"
+"Cursor is already open"
+"Cursor is not open"
+"Undeclared variable: %s"
+"Wrong number of FETCH variables"
+"No data to FETCH"

sql/share/norwegian-ny/errmsg.txt

@@ -303,3 +303,11 @@ character-set=latin1
 "Undefined CONDITION: %s"
 "No RETURN found in FUNCTION %s"
 "FUNCTION %s ended without RETURN"
+"Cursor statement must be a SELECT"
+"Cursor SELECT must not have INTO"
+"Undefined CURSOR: %s"
+"Cursor is already open"
+"Cursor is not open"
+"Undeclared variable: %s"
+"Wrong number of FETCH variables"
+"No data to FETCH"

sql/share/norwegian/errmsg.txt

@@ -303,3 +303,11 @@ character-set=latin1
 "Undefined CONDITION: %s"
 "No RETURN found in FUNCTION %s"
 "FUNCTION %s ended without RETURN"
+"Cursor statement must be a SELECT"
+"Cursor SELECT must not have INTO"
+"Undefined CURSOR: %s"
+"Cursor is already open"
+"Cursor is not open"
+"Undeclared variable: %s"
+"Wrong number of FETCH variables"
+"No data to FETCH"

sql/share/polish/errmsg.txt

@@ -305,3 +305,11 @@ character-set=latin2
 "Undefined CONDITION: %s"
 "No RETURN found in FUNCTION %s"
 "FUNCTION %s ended without RETURN"
+"Cursor statement must be a SELECT"
+"Cursor SELECT must not have INTO"
+"Undefined CURSOR: %s"
+"Cursor is already open"
+"Cursor is not open"
+"Undeclared variable: %s"
+"Wrong number of FETCH variables"
+"No data to FETCH"

sql/share/portuguese/errmsg.txt

@@ -302,3 +302,11 @@ character-set=latin1
 "Undefined CONDITION: %s"
 "No RETURN found in FUNCTION %s"
 "FUNCTION %s ended without RETURN"
+"Cursor statement must be a SELECT"
+"Cursor SELECT must not have INTO"
+"Undefined CURSOR: %s"
+"Cursor is already open"
+"Cursor is not open"
+"Undeclared variable: %s"
+"Wrong number of FETCH variables"
+"No data to FETCH"

sql/share/romanian/errmsg.txt

@@ -305,3 +305,11 @@ character-set=latin2
 "Undefined CONDITION: %s"
 "No RETURN found in FUNCTION %s"
 "FUNCTION %s ended without RETURN"
+"Cursor statement must be a SELECT"
+"Cursor SELECT must not have INTO"
+"Undefined CURSOR: %s"
+"Cursor is already open"
+"Cursor is not open"
+"Undeclared variable: %s"
+"Wrong number of FETCH variables"
+"No data to FETCH"

sql/share/russian/errmsg.txt

@@ -303,3 +303,11 @@ character-set=koi8r
 "Undefined CONDITION: %s"
 "No RETURN found in FUNCTION %s"
 "FUNCTION %s ended without RETURN"
+"Cursor statement must be a SELECT"
+"Cursor SELECT must not have INTO"
+"Undefined CURSOR: %s"
+"Cursor is already open"
+"Cursor is not open"
+"Undeclared variable: %s"
+"Wrong number of FETCH variables"
+"No data to FETCH"

sql/share/serbian/errmsg.txt

@@ -296,3 +296,11 @@ character-set=cp1250
 "Undefined CONDITION: %s"
 "No RETURN found in FUNCTION %s"
 "FUNCTION %s ended without RETURN"
+"Cursor statement must be a SELECT"
+"Cursor SELECT must not have INTO"
+"Undefined CURSOR: %s"
+"Cursor is already open"
+"Cursor is not open"
+"Undeclared variable: %s"
+"Wrong number of FETCH variables"
+"No data to FETCH"

sql/share/slovak/errmsg.txt

@@ -309,3 +309,11 @@ character-set=latin2
 "Undefined CONDITION: %s"
 "No RETURN found in FUNCTION %s"
 "FUNCTION %s ended without RETURN"
+"Cursor statement must be a SELECT"
+"Cursor SELECT must not have INTO"
+"Undefined CURSOR: %s"
+"Cursor is already open"
+"Cursor is not open"
+"Undeclared variable: %s"
+"Wrong number of FETCH variables"
+"No data to FETCH"

sql/share/spanish/errmsg.txt

@@ -303,3 +303,11 @@ character-set=latin1
 "Undefined CONDITION: %s"
 "No RETURN found in FUNCTION %s"
 "FUNCTION %s ended without RETURN"
+"Cursor statement must be a SELECT"
+"Cursor SELECT must not have INTO"
+"Undefined CURSOR: %s"
+"Cursor is already open"
+"Cursor is not open"
+"Undeclared variable: %s"
+"Wrong number of FETCH variables"
+"No data to FETCH"

sql/share/swedish/errmsg.txt

@@ -301,3 +301,11 @@ character-set=latin1
 "Undefined CONDITION: %s"
 "No RETURN found in FUNCTION %s"
 "FUNCTION %s ended without RETURN"
+"Cursor statement must be a SELECT"
+"Cursor SELECT must not have INTO"
+"Undefined CURSOR: %s"
+"Cursor is already open"
+"Cursor is not open"
+"Undeclared variable: %s"
+"Wrong number of FETCH variables"
+"No data to FETCH"

sql/share/ukrainian/errmsg.txt

@@ -306,3 +306,11 @@ character-set=koi8u
 "Undefined CONDITION: %s"
 "No RETURN found in FUNCTION %s"
 "FUNCTION %s ended without RETURN"
+"Cursor statement must be a SELECT"
+"Cursor SELECT must not have INTO"
+"Undefined CURSOR: %s"
+"Cursor is already open"
+"Cursor is not open"
+"Undeclared variable: %s"
+"Wrong number of FETCH variables"
+"No data to FETCH"

sql/sp_head.cc

@@ -289,6 +289,7 @@ sp_head::execute_function(THD *thd, Item **argp, uint argcount, Item **resp)
   uint csize = m_pcont->max_framesize();
   uint params = m_pcont->params();
   uint hmax = m_pcont->handlers();
+  uint cmax = m_pcont->cursors();
   sp_rcontext *octx = thd->spcont;
   sp_rcontext *nctx = NULL;
   uint i;
@@ -304,7 +305,7 @@ sp_head::execute_function(THD *thd, Item **argp, uint argcount, Item **resp)
   }
 
   // QQ Should have some error checking here? (types, etc...)
-  nctx= new sp_rcontext(csize, hmax);
+  nctx= new sp_rcontext(csize, hmax, cmax);
   for (i= 0 ; i < params && i < argcount ; i++)
   {
     sp_pvar_t *pvar = m_pcont->find_pvar(i);
@@ -335,6 +336,7 @@ sp_head::execute_function(THD *thd, Item **argp, uint argcount, Item **resp)
     }
   }
 
+  nctx->pop_all_cursors();	// To avoid memory leaks after an error
   thd->spcont= octx;
   DBUG_RETURN(ret);
 }
@@ -349,6 +351,7 @@ sp_head::execute_procedure(THD *thd, List<Item> *args)
   uint csize = m_pcont->max_framesize();
   uint params = m_pcont->params();
   uint hmax = m_pcont->handlers();
+  uint cmax = m_pcont->cursors();
   sp_rcontext *octx = thd->spcont;
   sp_rcontext *nctx = NULL;
   my_bool tmp_octx = FALSE;	// True if we have allocated a temporary octx
@@ -360,17 +363,17 @@ sp_head::execute_procedure(THD *thd, List<Item> *args)
     DBUG_RETURN(-1);
   }
 
-  if (csize > 0 || hmax > 0)
+  if (csize > 0 || hmax > 0 || cmax > 0)
   {
     uint i;
     List_iterator_fast<Item> li(*args);
     Item *it;
 
-    nctx = new sp_rcontext(csize, hmax);
+    nctx= new sp_rcontext(csize, hmax, cmax);
     if (! octx)
     {				// Create a temporary old context
-      octx = new sp_rcontext(csize, hmax);
-      tmp_octx = TRUE;
+      octx= new sp_rcontext(csize, hmax, cmax);
+      tmp_octx= TRUE;
     }
     // QQ: Should do type checking?
     for (i = 0 ; (it= li++) && i < params ; i++)
@@ -443,13 +446,14 @@ sp_head::execute_procedure(THD *thd, List<Item> *args)
 	}
       }
     }
-
-    if (tmp_octx)
-      thd->spcont= NULL;
-    else
-      thd->spcont= octx;
   }
 
+  if (tmp_octx)
+    octx= NULL;
+  if (nctx)
+    nctx->pop_all_cursors();	// To avoid memory leaks after an error
+  thd->spcont= octx;
+
   DBUG_RETURN(ret);
 }
 
@@ -596,12 +600,20 @@ sp_instr_stmt::execute(THD *thd, uint *nextp)
 {
   DBUG_ENTER("sp_instr_stmt::execute");
   DBUG_PRINT("info", ("command: %d", m_lex->sql_command));
+  int res= exec_stmt(thd, m_lex);
+  *nextp = m_ip+1;
+  DBUG_RETURN(res);
+}
+
+int
+sp_instr_stmt::exec_stmt(THD *thd, LEX *lex)
+{
   LEX *olex;			// The other lex
   Item *freelist;
   int res;
 
   olex= thd->lex;		// Save the other lex
-  thd->lex= m_lex;		// Use my own lex
+  thd->lex= lex;		// Use my own lex
   thd->lex->thd = thd;		// QQ Not reentrant!
   thd->lex->unit.thd= thd;	// QQ Not reentrant
   freelist= thd->free_list;
@@ -610,10 +622,19 @@ sp_instr_stmt::execute(THD *thd, uint *nextp)
 
   // Copy WHERE clause pointers to avoid damaging by optimisation
   // Also clear ref_pointer_arrays.
-  for (SELECT_LEX *sl= m_lex->all_selects_list ;
+  for (SELECT_LEX *sl= lex->all_selects_list ;
        sl ;
        sl= sl->next_select_in_list())
   {
+    List_iterator_fast<Item> li(sl->item_list);
+
+    if (sl->with_wild)
+    {
+      // Copy item_list
+      sl->item_list_copy.empty();
+      while (Item *it= li++)
+	sl->item_list_copy.push_back(it);
+    }
     sl->ref_pointer_array= 0;
     if (sl->prep_where)
       sl->where= sl->prep_where->copy_andor_structure(thd);
@@ -628,11 +649,22 @@ sp_instr_stmt::execute(THD *thd, uint *nextp)
     close_thread_tables(thd);			/* Free tables */
   }
 
+  for (SELECT_LEX *sl= lex->all_selects_list ;
+       sl ;
+       sl= sl->next_select_in_list())
+  {
+    if (sl->with_wild)
+    {
+      // Restore item_list
+      sl->item_list.empty();
+      while (Item *it= sl->item_list_copy.pop())
+	sl->item_list.push_back(it);
+    }
+  }
   thd->lex= olex;		// Restore the other lex
   thd->free_list= freelist;
 
-  *nextp = m_ip+1;
-  DBUG_RETURN(res);
+  return res;
 }
 
 //
@@ -747,3 +779,96 @@ sp_instr_hreturn::execute(THD *thd, uint *nextp)
   *nextp= thd->spcont->pop_hstack();
   DBUG_RETURN(0);
 }
+
+//
+// sp_instr_cpush
+//
+int
+sp_instr_cpush::execute(THD *thd, uint *nextp)
+{
+  DBUG_ENTER("sp_instr_cpush::execute");
+  thd->spcont->push_cursor(m_lex);
+  *nextp= m_ip+1;
+  DBUG_RETURN(0);
+}
+
+sp_instr_cpush::~sp_instr_cpush()
+{
+  if (m_lex)
+    delete m_lex;
+}
+
+//
+// sp_instr_cpop
+//
+int
+sp_instr_cpop::execute(THD *thd, uint *nextp)
+{
+  DBUG_ENTER("sp_instr_cpop::execute");
+  thd->spcont->pop_cursors(m_count);
+  *nextp= m_ip+1;
+  DBUG_RETURN(0);
+}
+
+//
+// sp_instr_copen
+//
+int
+sp_instr_copen::execute(THD *thd, uint *nextp)
+{
+  sp_cursor *c= thd->spcont->get_cursor(m_cursor);
+  int res;
+  DBUG_ENTER("sp_instr_copen::execute");
+
+  if (! c)
+    res= -1;
+  else
+  {
+    LEX *lex= c->pre_open(thd);
+
+    if (! lex)
+      res= -1;
+    else
+      res= exec_stmt(thd, lex);
+    c->post_open(thd, (res == 0 ? TRUE : FALSE));
+  }
+
+  *nextp= m_ip+1;
+  DBUG_RETURN(res);
+}
+
+//
+// sp_instr_cclose
+//
+int
+sp_instr_cclose::execute(THD *thd, uint *nextp)
+{
+  sp_cursor *c= thd->spcont->get_cursor(m_cursor);
+  int res;
+  DBUG_ENTER("sp_instr_cclose::execute");
+
+  if (! c)
+    res= -1;
+  else
+    res= c->close(thd);
+  *nextp= m_ip+1;
+  DBUG_RETURN(res);
+}
+
+//
+// sp_instr_cfetch
+//
+int
+sp_instr_cfetch::execute(THD *thd, uint *nextp)
+{
+  sp_cursor *c= thd->spcont->get_cursor(m_cursor);
+  int res;
+  DBUG_ENTER("sp_instr_cfetch::execute");
+
+  if (! c)
+    res= -1;
+  else
+    res= c->fetch(thd, &m_varlist);
+  *nextp= m_ip+1;
+  DBUG_RETURN(res);
+}

sql/sp_head.h

@@ -33,10 +33,9 @@ Item_result
 sp_map_result_type(enum enum_field_types type);
 
 struct sp_label;
-
 class sp_instr;
-
 struct sp_cond_type;
+struct sp_pvar;
 
 class sp_head : public Sql_alloc
 {
@@ -278,6 +277,10 @@ class sp_instr_stmt : public sp_instr
     return m_lex;
   }
 
+protected:
+
+  int exec_stmt(THD *thd, LEX *lex); // Execute a statement
+
 private:
 
   LEX *m_lex;			// My own lex
@@ -503,4 +506,126 @@ class sp_instr_hreturn : public sp_instr
 }; // class sp_instr_hreturn : public sp_instr
 
 
+class sp_instr_cpush : public sp_instr
+{
+  sp_instr_cpush(const sp_instr_cpush &); /* Prevent use of these */
+  void operator=(sp_instr_cpush &);
+
+public:
+
+  sp_instr_cpush(uint ip, LEX *lex)
+    : sp_instr(ip), m_lex(lex)
+  {}
+
+  virtual ~sp_instr_cpush();
+
+  virtual int execute(THD *thd, uint *nextp);
+
+private:
+
+  LEX *m_lex;
+
+}; // class sp_instr_cpush : public sp_instr
+
+
+class sp_instr_cpop : public sp_instr
+{
+  sp_instr_cpop(const sp_instr_cpop &); /* Prevent use of these */
+  void operator=(sp_instr_cpop &);
+
+public:
+
+  sp_instr_cpop(uint ip, uint count)
+    : sp_instr(ip), m_count(count)
+  {}
+
+  virtual ~sp_instr_cpop()
+  {}
+
+  virtual int execute(THD *thd, uint *nextp);
+
+private:
+
+  uint m_count;
+
+}; // class sp_instr_cpop : public sp_instr
+
+
+class sp_instr_copen : public sp_instr_stmt
+{
+  sp_instr_copen(const sp_instr_copen &); /* Prevent use of these */
+  void operator=(sp_instr_copen &);
+
+public:
+
+  sp_instr_copen(uint ip, uint c)
+    : sp_instr_stmt(ip), m_cursor(c)
+  {}
+
+  virtual ~sp_instr_copen()
+  {}
+
+  virtual int execute(THD *thd, uint *nextp);
+
+private:
+
+  uint m_cursor;		// Stack index
+
+}; // class sp_instr_copen : public sp_instr_stmt
+
+
+class sp_instr_cclose : public sp_instr
+{
+  sp_instr_cclose(const sp_instr_cclose &); /* Prevent use of these */
+  void operator=(sp_instr_cclose &);
+
+public:
+
+  sp_instr_cclose(uint ip, uint c)
+    : sp_instr(ip), m_cursor(c)
+  {}
+
+  virtual ~sp_instr_cclose()
+  {}
+
+  virtual int execute(THD *thd, uint *nextp);
+
+private:
+
+  uint m_cursor;
+
+}; // class sp_instr_cclose : public sp_instr
+
+
+class sp_instr_cfetch : public sp_instr
+{
+  sp_instr_cfetch(const sp_instr_cfetch &); /* Prevent use of these */
+  void operator=(sp_instr_cfetch &);
+
+public:
+
+  sp_instr_cfetch(uint ip, uint c)
+    : sp_instr(ip), m_cursor(c)
+  {
+    m_varlist.empty();
+  }
+
+  virtual ~sp_instr_cfetch()
+  {}
+
+  virtual int execute(THD *thd, uint *nextp);
+
+  void add_to_varlist(struct sp_pvar *var)
+  {
+    m_varlist.push_back(var);
+  }
+
+private:
+
+  uint m_cursor;
+  List<struct sp_pvar> m_varlist;
+
+}; // class sp_instr_cfetch : public sp_instr
+
+
 #endif /* _SP_HEAD_H_ */

sql/sp_pcontext.cc

@@ -27,10 +27,11 @@
 #include "sp_head.h"
 
 sp_pcontext::sp_pcontext()
-  : Sql_alloc(), m_params(0), m_framesize(0), m_handlers(0), m_genlab(0)
+  : Sql_alloc(), m_params(0), m_framesize(0), m_handlers(0), m_cursmax(0)
 {
   VOID(my_init_dynamic_array(&m_pvar, sizeof(sp_pvar_t *), 16, 8));
   VOID(my_init_dynamic_array(&m_cond, sizeof(sp_cond_type_t *), 16, 8));
+  VOID(my_init_dynamic_array(&m_cursor, sizeof(LEX_STRING), 16, 8));
   m_label.empty();
 }
 
@@ -39,6 +40,7 @@ sp_pcontext::destroy()
 {
   delete_dynamic(&m_pvar);
   delete_dynamic(&m_cond);
+  delete_dynamic(&m_cursor);
   m_label.empty();
 }
 
@@ -124,8 +126,6 @@ sp_pcontext::push_cond(LEX_STRING *name, sp_cond_type_t *val)
 
   if (p)
   {
-    if (m_cond.elements == m_framesize)
-      m_framesize += 1;
     p->name.str= name->str;
     p->name.length= name->length;
     p->val= val;
@@ -155,3 +155,39 @@ sp_pcontext::find_cond(LEX_STRING *name)
   }
   return NULL;
 }
+
+void
+sp_pcontext::push_cursor(LEX_STRING *name)
+{
+  LEX_STRING n;
+
+  n.str= name->str;
+  n.length= name->length;
+  insert_dynamic(&m_cursor, (gptr)&n);
+  if (m_cursor.elements > m_cursmax)
+    m_cursmax= m_cursor.elements;
+}
+
+/*
+ * See comment for find_pvar() above
+ */
+my_bool
+sp_pcontext::find_cursor(LEX_STRING *name, uint *poff)
+{
+  uint i = m_cursor.elements;
+
+  while (i-- > 0)
+  {
+    LEX_STRING n;
+
+    get_dynamic(&m_cursor, (gptr)&n, i);
+    if (my_strnncoll(system_charset_info,
+		     (const uchar *)name->str, name->length,
+		     (const uchar *)n.str, n.length) == 0)
+    {
+      *poff= i;
+      return TRUE;
+    }
+  }
+  return FALSE;
+}

sql/sp_pcontext.h

@@ -29,7 +29,7 @@ typedef enum
   sp_param_inout
 } sp_param_mode_t;
 
-typedef struct
+typedef struct sp_pvar
 {
   LEX_STRING name;
   enum enum_field_types type;
@@ -200,17 +200,41 @@ class sp_pcontext : public Sql_alloc
     return m_handlers;
   }
 
+  //
+  // Cursors
+  //
+
+  void
+  push_cursor(LEX_STRING *name);
+
+  my_bool
+  find_cursor(LEX_STRING *name, uint *poff);
+
+  inline void
+  pop_cursor(uint num)
+  {
+    while (num--)
+      pop_dynamic(&m_cursor);
+  }
+
+  inline uint
+  cursors()
+  {
+    return m_cursmax;
+  }
+
 private:
 
   uint m_params;		// The number of parameters
   uint m_framesize;		// The maximum framesize
   uint m_handlers;		// The total number of handlers
+  uint m_cursmax;		// The maximum number of cursors
 
   DYNAMIC_ARRAY m_pvar;		// Parameters/variables
   DYNAMIC_ARRAY m_cond;		// Conditions
+  DYNAMIC_ARRAY m_cursor;	// Cursors
 
   List<sp_label_t> m_label;	// The label list
-  uint m_genlab;		// Gen. label counter
 
 }; // class sp_pcontext : public Sql_alloc
 

sql/sp_rcontext.cc

@@ -23,16 +23,20 @@
 #endif
 
 #include "mysql_priv.h"
+#include "mysql.h"
+#include "sp_head.h"
 #include "sp_rcontext.h"
 #include "sp_pcontext.h"
 
-sp_rcontext::sp_rcontext(uint fsize, uint hmax)
-  : m_count(0), m_fsize(fsize), m_result(NULL), m_hcount(0), m_hsp(0)
+sp_rcontext::sp_rcontext(uint fsize, uint hmax, uint cmax)
+  : m_count(0), m_fsize(fsize), m_result(NULL), m_hcount(0), m_hsp(0),
+    m_hfound(-1), m_ccount(0)
 {
   m_frame= (Item **)sql_alloc(fsize * sizeof(Item*));
   m_outs= (int *)sql_alloc(fsize * sizeof(int));
   m_handler= (sp_handler_t *)sql_alloc(hmax * sizeof(sp_handler_t));
   m_hstack= (uint *)sql_alloc(hmax * sizeof(uint));
+  m_cstack= (sp_cursor **)sql_alloc(cmax * sizeof(sp_cursor *));
   m_saved.empty();
 }
 
@@ -93,3 +97,141 @@ sp_rcontext::restore_variables(uint fp)
   while (i-- > fp)
     m_frame[i]= m_saved.pop();
 }
+
+void
+sp_rcontext::push_cursor(LEX *lex)
+{
+  m_cstack[m_ccount++]= new sp_cursor(lex);
+}
+
+void
+sp_rcontext::pop_cursors(uint count)
+{
+  while (count--)
+  {
+    delete m_cstack[--m_ccount];
+  }
+}
+
+
+/*
+ *
+ *  sp_cursor
+ *
+ */
+
+// We have split this in two to make it easy for sp_instr_copen
+// to reuse the sp_instr::exec_stmt() code.
+LEX *
+sp_cursor::pre_open(THD *thd)
+{
+  int res;
+
+  if (m_isopen)
+  {
+    send_error(thd, ER_SP_CURSOR_ALREADY_OPEN);
+    return NULL;
+  }
+
+  bzero((char *)&m_mem_root, sizeof(m_mem_root));
+  init_alloc_root(&m_mem_root, MEM_ROOT_BLOCK_SIZE, MEM_ROOT_PREALLOC);
+  if ((m_prot= new Protocol_cursor(thd, &m_mem_root)) == NULL)
+    return NULL;
+
+  m_oprot= thd->protocol;	// Save the original protocol
+  thd->protocol= m_prot;
+
+  m_ovio= thd->net.vio;		// Prevent send_eof()
+  thd->net.vio= 0;
+  return m_lex;
+}
+
+void
+sp_cursor::post_open(THD *thd, my_bool isopen)
+{
+  thd->net.vio= m_ovio;		// Restore the originals
+  thd->protocol= m_oprot;
+  m_isopen= isopen;
+  m_current_row= m_prot->data;
+}
+
+int
+sp_cursor::close(THD *thd)
+{
+  if (! m_isopen)
+  {
+    send_error(thd, ER_SP_CURSOR_NOT_OPEN);
+    return -1;
+  }
+  destroy();
+  return 0;
+}
+
+void
+sp_cursor::destroy()
+{
+  delete m_prot;
+  m_prot= NULL;
+  free_root(&m_mem_root, MYF(0));
+  bzero((char *)&m_mem_root, sizeof(m_mem_root));
+  m_isopen= FALSE;
+}
+
+int
+sp_cursor::fetch(THD *thd, List<struct sp_pvar> *vars)
+{
+  List_iterator_fast<struct sp_pvar> li(*vars);
+  sp_pvar_t *pv;
+  MYSQL_ROW row;
+  uint fldcount;
+  MYSQL_FIELD *fields= m_prot->fields;
+
+  if (! m_isopen)
+  {
+    send_error(thd, ER_SP_CURSOR_NOT_OPEN);
+    return -1;
+  }
+
+  if (m_current_row == NULL)
+  {
+    send_error(thd, ER_SP_FETCH_NO_DATA);
+    return -1;
+  }
+
+  row= m_current_row->data;
+  for (fldcount= 0 ; (pv= li++) ; fldcount++)
+  {
+    Item *it;
+    const char *s;
+
+    if (fldcount >= m_prot->get_field_count())
+    {
+      send_error(thd, ER_SP_WRONG_NO_OF_FETCH_ARGS);
+      return -1;
+    }
+    s= row[fldcount];
+    switch (sp_map_result_type(pv->type))
+    {
+    case INT_RESULT:
+      it= new Item_int(s);
+      break;
+    case REAL_RESULT:
+      it= new Item_real(s, strlen(s));
+      break;
+    default:
+      {
+	uint len= strlen(s);
+	it= new Item_string(thd->strmake(s, len), len, thd->db_charset);
+	break;
+      }
+    }
+    thd->spcont->set_item(pv->offset, it);
+  }
+  if (fldcount < m_prot->get_field_count())
+  {
+    send_error(thd, ER_SP_WRONG_NO_OF_FETCH_ARGS);
+    return -1;
+  }
+  m_current_row= m_current_row->next;
+  return 0;
+}

sql/sp_rcontext.h

@@ -23,6 +23,8 @@
 #endif
 
 struct sp_cond_type;
+struct sp_cursor;
+struct sp_pvar;
 
 #define SP_HANDLER_NONE      0
 #define SP_HANDLER_EXIT      1
@@ -44,7 +46,7 @@ class sp_rcontext : public Sql_alloc
 
  public:
 
-  sp_rcontext(uint fsize, uint hmax);
+  sp_rcontext(uint fsize, uint hmax, uint cmax);
 
   ~sp_rcontext()
   {
@@ -155,22 +157,93 @@ class sp_rcontext : public Sql_alloc
   void
   restore_variables(uint fp);
 
+  void
+  push_cursor(LEX *lex);
+
+  void
+  pop_cursors(uint count);
+
+  void
+  pop_all_cursors()
+  {
+    pop_cursors(m_ccount);
+  }
+
+  inline sp_cursor *
+  get_cursor(uint i)
+  {
+    return m_cstack[i];
+  }
+
 private:
 
   uint m_count;
   uint m_fsize;
   Item **m_frame;
   int  *m_outs;
+
   Item *m_result;		// For FUNCTIONs
+
   sp_handler_t *m_handler;
   uint m_hcount;
   uint *m_hstack;
   uint m_hsp;
-
   int m_hfound;			// Set by find_handler; -1 if not found
-
   List<Item> m_saved;		// Saved variables
 
+  sp_cursor **m_cstack;
+  uint m_ccount;
+
 }; // class sp_rcontext : public Sql_alloc
 
+
+class sp_cursor : public Sql_alloc
+{
+public:
+
+  sp_cursor(LEX *lex)
+    : m_lex(lex), m_isopen(0), m_current_row(NULL)
+  {
+    /* Empty */
+  }
+
+  virtual ~sp_cursor()
+  {
+    destroy();
+  }
+
+  // We have split this in two to make it easy for sp_instr_copen
+  // to reuse the sp_instr::exec_stmt() code.
+  LEX *
+  pre_open(THD *thd);
+  void
+  post_open(THD *thd, my_bool isopen);
+
+  int
+  close(THD *thd);
+
+  inline my_bool
+  is_open()
+  {
+    return m_isopen;
+  }
+
+  int
+  fetch(THD *, List<struct sp_pvar> *vars);
+
+private:
+
+  MEM_ROOT m_mem_root;		// My own mem_root
+  LEX *m_lex;
+  Protocol_cursor *m_prot;
+  my_bool m_isopen;
+  Vio *m_ovio;			// Original vio
+  Protocol *m_oprot;		// Original protcol
+  MYSQL_ROWS *m_current_row;
+  
+  void
+  destroy();
+
+}; // class sp_cursor : public Sql_alloc
+
 #endif /* _SP_RCONTEXT_H_ */

sql/sql_lex.h

@@ -348,6 +348,7 @@ class st_select_lex: public st_select_lex_node
   enum olap_type olap;
   SQL_LIST	      table_list, group_list;   /* FROM & GROUP BY clauses */
   List<Item>          item_list; /* list of fields & expressions */
+  List<Item>          item_list_copy; /* For SPs */
   List<String>        interval_list, use_index, *use_index_ptr,
 		      ignore_index, *ignore_index_ptr;
   /* 

sql/sql_yacc.yy

@@ -86,7 +86,8 @@ inline Item *or_or_concat(THD *thd, Item* A, Item* B)
   st_select_lex *select_lex;
   chooser_compare_func_creator boolfunc2creator;
   struct sp_cond_type *spcondtype;
-  struct { int vars, conds, hndlrs; } spblock;
+  struct { int vars, conds, hndlrs, curs; } spblock;
+  struct st_lex *lex;
 }
 
 %{
@@ -748,6 +749,7 @@ END_OF_INPUT
 %type <num>  sp_decl_idents sp_opt_inout sp_handler_type sp_hcond_list
 %type <spcondtype> sp_cond sp_hcond
 %type <spblock> sp_decls sp_decl
+%type <lex> sp_cursor_stmt
 
 %type <NONE>
 	'-' '+' '*' '/' '%' '(' ')'
@@ -1189,13 +1191,14 @@ sp_proc_stmts:
 sp_decls:
 	  /* Empty */
 	  {
-	    $$.vars= $$.conds= $$.hndlrs= 0;
+	    $$.vars= $$.conds= $$.hndlrs= $$.curs= 0;
 	  }
 	| sp_decls sp_decl ';'
 	  {
 	    $$.vars= $1.vars + $2.vars;
 	    $$.conds= $1.conds + $2.conds;
 	    $$.hndlrs= $1.hndlrs + $2.hndlrs;
+	    $$.curs= $1.curs + $2.curs;
 	  }
 	;
 
@@ -1222,12 +1225,12 @@ sp_decl:
 	      }
 	    }
 	    $$.vars= $2;
-	    $$.conds= $$.hndlrs= 0;
+	    $$.conds= $$.hndlrs= $$.curs= 0;
 	  }
 	| DECLARE_SYM ident CONDITION_SYM FOR_SYM sp_cond
 	  {
 	    YYTHD->lex->spcont->push_cond(&$2, $5);
-	    $$.vars= $$.hndlrs= 0;
+	    $$.vars= $$.hndlrs= $$.curs= 0;
 	    $$.conds= 1;
 	  }
 	| DECLARE_SYM sp_handler_type HANDLER_SYM FOR_SYM
@@ -1260,14 +1263,49 @@ sp_decl:
 	      sp->push_backpatch(i, lex->spcont->last_label()); /* Block end */
 	    }
 	    lex->sphead->backpatch(hlab);
-	    $$.vars= $$.conds= 0;
+	    $$.vars= $$.conds= $$.curs= 0;
 	    $$.hndlrs= $6;
 	  }
-/* QQ Not yet
 	| DECLARE_SYM ident CURSOR_SYM FOR_SYM sp_cursor_stmt
 	  {
+	    LEX *lex= Lex;
+	    sp_head *sp= lex->sphead;
+	    sp_instr_cpush *i= new sp_instr_cpush(sp->instructions(), $5);
+
+	    sp->add_instr(i);
+	    lex->spcont->push_cursor(&$2);
 	    $$.vars= $$.conds= $$.hndlrs= 0;
-	  }*/
+	    $$.curs= 1;
+	  }
+	;
+
+sp_cursor_stmt:
+	  {
+	    Lex->sphead->reset_lex(YYTHD);
+
+	    /* We use statement here just be able to get a better
+	       error message. Using 'select' works too, but will then
+	       result in a generic "syntax error" if a non-select
+	       statement is given. */
+	  }
+	  statement
+	  {
+	    LEX *lex= Lex;
+
+	    if (lex->sql_command != SQLCOM_SELECT)
+	    {
+	      send_error(YYTHD, ER_SP_BAD_CURSOR_QUERY);
+	      YYABORT;
+	    }
+	    if (lex->result)
+	    {
+	      send_error(YYTHD, ER_SP_BAD_CURSOR_SELECT);
+	      YYABORT;
+	    }
+	    lex->sp_lex_in_use= TRUE;
+	    $$= lex;
+	    lex->sphead->restore_lex(YYTHD);
+	  }
 	;
 
 sp_handler_type:
@@ -1506,11 +1544,96 @@ sp_proc_stmt:
 	    }
 	  }
 	| OPEN_SYM ident
-	  {}
-	| FETCH_SYM ident INTO select_var_list_init
-	  {}
+	  {
+	    LEX *lex= Lex;
+	    sp_head *sp= lex->sphead;
+	    uint offset;
+	    sp_instr_copen *i;
+
+	    if (! lex->spcont->find_cursor(&$2, &offset))
+	    {
+	      net_printf(YYTHD, ER_SP_CURSOR_MISMATCH, $2.str);
+	      YYABORT;
+	    }
+	    i= new sp_instr_copen(sp->instructions(), offset);
+	    sp->add_instr(i);
+	  }
+	| FETCH_SYM ident INTO
+	  {
+	    LEX *lex= Lex;
+	    sp_head *sp= lex->sphead;
+	    uint offset;
+	    sp_instr_cfetch *i;
+
+	    if (! lex->spcont->find_cursor(&$2, &offset))
+	    {
+	      net_printf(YYTHD, ER_SP_CURSOR_MISMATCH, $2.str);
+	      YYABORT;
+	    }
+	    i= new sp_instr_cfetch(sp->instructions(), offset);
+	    sp->add_instr(i);
+	  }
+	  sp_fetch_list
+	  { }
 	| CLOSE_SYM ident
-	  {}
+	  {
+	    LEX *lex= Lex;
+	    sp_head *sp= lex->sphead;
+	    uint offset;
+	    sp_instr_cclose *i;
+
+	    if (! lex->spcont->find_cursor(&$2, &offset))
+	    {
+	      net_printf(YYTHD, ER_SP_CURSOR_MISMATCH, $2.str);
+	      YYABORT;
+	    }
+	    i= new sp_instr_cclose(sp->instructions(), offset);
+	    sp->add_instr(i);
+	  }
+	;
+
+sp_fetch_list:
+	  ident
+	  {
+	    LEX *lex= Lex;
+	    sp_head *sp= lex->sphead;
+	    sp_pcontext *spc= lex->spcont;
+	    sp_pvar_t *spv;
+
+	    if (!spc || !(spv = spc->find_pvar(&$1)))
+	    {
+	      net_printf(YYTHD, ER_SP_UNDECLARED_VAR, $1.str);
+	      YYABORT;
+	    }
+	    else
+	    { /* An SP local variable */
+	      sp_instr_cfetch *i= (sp_instr_cfetch *)sp->last_instruction();
+
+	      i->add_to_varlist(spv);
+	      spv->isset= TRUE;
+	    }
+	  }
+	|
+	  sp_fetch_list ',' ident
+	  {
+	    LEX *lex= Lex;
+	    sp_head *sp= lex->sphead;
+	    sp_pcontext *spc= lex->spcont;
+	    sp_pvar_t *spv;
+
+	    if (!spc || !(spv = spc->find_pvar(&$3)))
+	    {
+	      net_printf(YYTHD, ER_SP_UNDECLARED_VAR, $3.str);
+	      YYABORT;
+	    }
+	    else
+	    { /* An SP local variable */
+	      sp_instr_cfetch *i= (sp_instr_cfetch *)sp->last_instruction();
+
+	      i->add_to_varlist(spv);
+	      spv->isset= TRUE;
+	    }
+	  }
 	;
 
 sp_if:
@@ -1649,11 +1772,11 @@ sp_unlabeled_control:
   	    sp->backpatch(ctx->pop_label());
 	    ctx->pop_pvar($3.vars);
 	    ctx->pop_cond($3.conds);
+	    ctx->pop_cursor($3.curs);
 	    if ($3.hndlrs)
-	    {
-	      sp_instr_hpop *i= new sp_instr_hpop(sp->instructions(),$3.hndlrs);
-	      sp->add_instr(i);
-	    }
+	      sp->add_instr(new sp_instr_hpop(sp->instructions(),$3.hndlrs));
+	    if ($3.curs)
+	      sp->add_instr(new sp_instr_cpop(sp->instructions(), $3.curs));
 	  }
 	| LOOP_SYM
 	  sp_proc_stmts END LOOP_SYM
@@ -4206,7 +4329,7 @@ select_var_ident:
 	     sp_pvar_t *t;
 	     if (!(t=lex->spcont->find_pvar(&$1)))
 	     {
-	       send_error(lex->thd, ER_SYNTAX_ERROR);
+	       send_error(lex->thd, ER_SP_UNDECLARED_VAR);
 	       YYABORT;
 	     }
 	     if (! lex->result)