allow UPDATE and DELETE stetements with tables derived from subquery if they are not updated (BUG#2117)

allow delete table by alias in multi-delete statement

1 files changed, 36 insertions, 1 deletions

diff --git a/sql/sql_update.cc b/sql/sql_update.cc
index cdea32ad3f6..87421c482d5 100644
--- a/sql/sql_update.cc
+++ b/sql/sql_update.cc
@@ -434,13 +434,36 @@ int mysql_multi_update(THD *thd,
   fix_tables_pointers(thd->lex->all_selects_list);
 
   select_lex->select_limit= HA_POS_ERROR;
+
+  table_map item_tables= 0, derived_tables= 0;
+  if (thd->lex->derived_tables)
+  {
+    // Assign table map values to check updatability of derived tables
+    uint tablenr=0;
+    for (TABLE_LIST *table_list= (TABLE_LIST*) select_lex->table_list.first;
+	 table_list;
+	 table_list= table_list->next, tablenr++)
+    {
+      table_list->table->map= (table_map) 1 << tablenr;
+    }
+  }
   if (setup_fields(thd, 0, table_list, *fields, 1, 0, 0))
     DBUG_RETURN(-1);
+  if (thd->lex->derived_tables)
+  {
+    // Find tables used in items
+    List_iterator_fast<Item> it(*fields);
+    Item *item;
+    while ((item= it++))
+    {
+      item_tables|= item->used_tables();
+    }
+  }
 
   /*
     Count tables and setup timestamp handling
   */
-  for (tl= select_lex->get_table_list() ; tl ; tl=tl->next)
+  for (tl= select_lex->get_table_list() ; tl ; tl= tl->next)
   {
     TABLE *table= tl->table;
     if (table->timestamp_field)
@@ -450,6 +473,18 @@ int mysql_multi_update(THD *thd,
       if (table->timestamp_field->query_id != thd->query_id)
 	table->time_stamp= table->timestamp_field->offset() +1;
     }
+    if (tl->derived)
+      derived_tables|= table->map;
+  }
+  if (thd->lex->derived_tables && (item_tables & derived_tables))
+  {
+    // find derived table which cause error
+    for (tl= select_lex->get_table_list() ; tl ; tl= tl->next)
+    {
+      if (tl->derived && (item_tables & tl->table->map))
+	my_printf_error(ER_NON_UPDATABLE_TABLE, ER(ER_NON_UPDATABLE_TABLE),
+			MYF(0), tl->alias, "UPDATE");
+    }
   }
 
   if (!(result=new multi_update(thd, table_list, fields, values,