1 files changed, 135 insertions, 0 deletions
diff --git a/sql/item_subselect.h b/sql/item_subselect.h
new file mode 100644
index 00000000000..88ea01f9c68
--- /dev/null
+++ b/sql/item_subselect.h
@@ -0,0 +1,135 @@
+/* Copyright (C) 2000 MySQL AB
+
+   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.
+
+   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.
+
+   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 */
+
+/* subselect Item */
+
+#ifdef __GNUC__
+#pragma interface			/* gcc class implementation */
+#endif
+
+class st_select_lex;
+class JOIN;
+class select_subselect;
+
+/* base class for subselects */
+
+class Item_subselect :public Item
+{
+protected:
+  uint max_columns;
+  my_bool assigned; /* value already assigned to subselect */
+  my_bool executed; /* simple subselect is executed */
+  my_bool optimized; /* simple subselect is optimized */
+  my_bool error; /* error in query */
+
+  int exec();
+  virtual void assign_null() 
+  {
+    null_value= 1;
+  }
+public:
+  st_select_lex *select_lex;
+  JOIN *join;
+  select_subselect *result;
+
+  Item_subselect(THD *thd, st_select_lex *select_lex,
+		 select_subselect* result);
+  Item_subselect(Item_subselect *item)
+  {
+    null_value= item->null_value;
+    decimals= item->decimals;
+    max_columns= item->max_columns;
+    assigned= item->assigned;
+    executed= item->executed;
+    select_lex= item->select_lex;
+    join= item->join;
+    result= item->result;
+    name= item->name;
+    error= item->error;
+  }
+  enum Type type() const;
+  bool is_null() { return null_value; }
+  void make_field (Send_field *);
+  bool fix_fields(THD *thd, TABLE_LIST *tables, Item **ref);
+  table_map used_tables() const;
+
+  friend class select_subselect;
+};
+
+
+/* single value subselect */
+
+class Item_singleval_subselect :public Item_subselect
+{
+protected:
+  longlong int_value;
+  double real_value;
+  enum Item_result res_type;
+
+  virtual void assign_null() 
+  {
+    null_value= 1;
+    int_value= 0;
+    real_value= 0;
+    max_length= 4;
+    res_type= STRING_RESULT;
+  }
+public:
+  Item_singleval_subselect(THD *thd, st_select_lex *select_lex);
+  Item_singleval_subselect(Item_singleval_subselect *item):
+    Item_subselect(item)
+  {
+    int_value= item->int_value;
+    real_value= item->real_value;
+    max_length= item->max_length;
+    decimals= item->decimals;
+    res_type= item->res_type;
+  }
+  double val ();
+  longlong val_int ();
+  String *val_str (String *);
+  Item *new_item() { return new Item_singleval_subselect(this); }
+  enum Item_result result_type() const { return res_type; }
+
+  friend class select_singleval_subselect;
+};
+
+/* exists subselect */
+
+class Item_exists_subselect :public Item_subselect
+{
+protected:
+  longlong value;
+
+  virtual void assign_null() 
+  {
+    value= 0;
+  }
+public:
+  Item_exists_subselect(THD *thd, st_select_lex *select_lex);
+  Item_exists_subselect(Item_exists_subselect *item):
+    Item_subselect(item)
+  {
+    value= item->value;
+  }
+  Item *new_item() { return new Item_exists_subselect(this); }
+  enum Item_result result_type() const { return INT_RESULT;}
+  longlong val_int();
+  double val();
+  String *val_str(String*);
+
+  friend class select_exists_subselect;
+};