DATE,TIME and DATETIME SQL typecasts

mysql-test/r/create.result

@@ -86,4 +86,11 @@ c	date			0000-00-00
 d	bigint(17)			0	
 e	double(18,1)			0.0	
 f	bigint(17)			0	
+drop table t2;
+create table t2 select DATE "2001-12-29" as d, TIME "20:45:11" as t, DATETIME "2001-12-29  20:45:11" as dt;
+describe t2;
+Field	Type	Null	Key	Default	Extra
+d	date			0000-00-00	
+t	time			00:00:00	
+dt	datetime			0000-00-00 00:00:00	
 drop table t1,t2;

mysql-test/t/create.test

@@ -77,4 +77,7 @@ describe t2;
 drop table t2;
 create table t2 select now() as a , curtime() as b, curdate() as c , 1+1 as d , 1.0 + 1 as e , 33333333333333333 + 3 as f;
 describe t2;
+drop table t2;
+create table t2 select DATE "2001-12-29" as d, TIME "20:45:11" as t, DATETIME "2001-12-29  20:45:11" as dt;
+describe t2;
 drop table t1,t2;

sql/item_timefunc.h

@@ -375,7 +375,6 @@ class Item_func_sec_to_time :public Item_str_func
     if (!t_arg) return result_field;
     return   new Field_time(maybe_null, name, t_arg);
   }  
-
 };
 
 enum interval_type { INTERVAL_YEAR, INTERVAL_MONTH, INTERVAL_DAY,
@@ -414,3 +413,60 @@ class Item_extract :public Item_int_func
   const char *func_name() const { return "extract"; }
   void fix_length_and_dec();
 };
+
+class Item_date_typecast :public Item_str_func
+{
+public:
+  Item_date_typecast(Item *a) :Item_str_func(a) {}
+  const char *func_name() const { return "date_typecast"; }
+  String *val_str(String *a) { return (args[0]->val_str(a)); }
+  void fix_length_and_dec() { max_length=args[0]->max_length; }
+  void print(String *str) { print_op(str); }
+  void make_field(Send_field *tmp_field)
+  {
+    init_make_field(tmp_field,FIELD_TYPE_DATE);
+  }
+  Field *tmp_table_field(TABLE *t_arg)
+  {
+    if (!t_arg) return result_field;
+    return   new Field_date(maybe_null, name, t_arg);
+  }  
+};
+
+class Item_time_typecast :public Item_str_func
+{
+public:
+  Item_time_typecast(Item *a) :Item_str_func(a) {}
+  const char *func_name() const { return "time_typecast"; }
+  String *val_str(String *a) { return (args[0]->val_str(a)); }
+  void fix_length_and_dec() { max_length=args[0]->max_length; }
+  void print(String *str) { print_op(str); }
+  void make_field(Send_field *tmp_field)
+  {
+    init_make_field(tmp_field,FIELD_TYPE_TIME);
+  }
+  Field *tmp_table_field(TABLE *t_arg)
+  {
+    if (!t_arg) return result_field;
+    return   new Field_time(maybe_null, name, t_arg);
+  }  
+};
+
+class Item_datetime_typecast :public Item_str_func
+{
+public:
+  Item_datetime_typecast(Item *a) :Item_str_func(a) {}
+  const char *func_name() const { return "datetime_typecast"; }
+  String *val_str(String *a) { return (args[0]->val_str(a)); }
+  void fix_length_and_dec() { max_length=args[0]->max_length; }
+  void print(String *str) { print_op(str); }
+  void make_field(Send_field *tmp_field)
+  {
+    init_make_field(tmp_field,FIELD_TYPE_DATETIME);
+  }
+  Field *tmp_table_field(TABLE *t_arg)
+  {
+    if (!t_arg) return result_field;
+    return   new Field_datetime(maybe_null, name, t_arg);
+  }  
+};

sql/sql_yacc.yy

@@ -486,6 +486,9 @@ bool my_yyoverflow(short **a, YYSTYPE **b,int *yystacksize);
 %left	NEG '~'
 %right	NOT
 %right	BINARY
+%right  DATE_SYM
+%right  TIME_SYM
+%right  DATETIME
 
 %type <lex_str>
 	IDENT TEXT_STRING REAL_NUM FLOAT_NUM NUM LONG_NUM HEX_NUM LEX_HOSTNAME
@@ -1601,6 +1604,9 @@ simple_expr:
           { Select->ftfunc_list.push_back((Item_func_match *)
                    ($$=new Item_func_match_bool(*$2,$5))); }
 	| BINARY expr %prec NEG	{ $$= new Item_func_binary($2); }
+	| DATE_SYM  expr { $$= new Item_date_typecast($2); }
+	| TIME_SYM  expr { $$= new Item_time_typecast($2); }
+	| DATETIME  expr { $$= new Item_datetime_typecast($2); }
 	| CASE_SYM opt_expr WHEN_SYM when_list opt_else END
 	  { $$= new Item_func_case(* $4, $2, $5 ) }
 	| FUNC_ARG0 '(' ')'