cleanup: simplify multi-update's juggling with positions

introduce Item_temptable_rowid() that is used to store
table->file->position() in the temporary table record

1 files changed, 20 insertions, 1 deletions

diff --git a/sql/item_strfunc.h b/sql/item_strfunc.h
index b3462a60d36..1132a947587 100644
--- a/sql/item_strfunc.h
+++ b/sql/item_strfunc.h
@@ -1751,5 +1751,24 @@ public:
   { return get_item_copy<Item_func_dyncol_list>(thd, this); }
 };
 
-#endif /* ITEM_STRFUNC_INCLUDED */
+/*
+  this is used by JOIN_TAB::keep_current_rowid
+  and stores handler::position().
+  It has nothing to do with _rowid pseudo-column, that the parser supports.
+*/
+class Item_temptable_rowid :public Item_str_func
+{
+public:
+  TABLE *table;
+  Item_temptable_rowid(TABLE *table_arg);
+  const Type_handler *type_handler() const { return &type_handler_string; }
+  Field *create_tmp_field(bool group, TABLE *table)
+  { return create_table_field_from_handler(table); }
+  String *val_str(String *str);
+  const char *func_name() const { return "<rowid>"; }
+  void fix_length_and_dec();
+  Item *get_copy(THD *thd)
+  { return get_item_copy<Item_temptable_rowid>(thd, this); }
+};
 
+#endif /* ITEM_STRFUNC_INCLUDED */