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Merge

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sql/sql_select.cc:
  Auto merged
sql/sql_update.cc:
  Auto merged
mysql-test/r/multi_update.result:
  SCCS merged
mysql-test/t/multi_update.test:
  SCCS merged
This commit is contained in:
unknown
2003-12-13 04:04:38 +02:00
parent cbc18a76c8 759ea82ee1
commit db37aa2297
40 changed files with 571 additions and 66 deletions
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22
sql/sql_update.cc
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@@ -544,6 +544,26 @@ int multi_update::prepare(List<Item> &not_used_values)
for (i=0 ; i < table_count ; i++)
set_if_bigger(max_fields, fields_for_table[i]->elements);
copy_field= new Copy_field[max_fields];
/*
Mark all copies of tables that are updates to ensure that
init_read_record() will not try to enable a cache on them
The problem is that for queries like
UPDATE t1, t1 AS t2 SET t1.b=t2.c WHERE t1.a=t2.a;
the row buffer may contain things that doesn't match what is on disk
which will cause an error when reading a row.
(This issue is mostly relevent for MyISAM tables)
*/
for (table_ref= all_tables; table_ref; table_ref=table_ref->next)
{
TABLE *table=table_ref->table;
if (!(tables_to_update & table->map) &&
check_dup(table_ref->db, table_ref->real_name, update_tables))
table->no_cache= 1; // Disable row cache
}
DBUG_RETURN(thd->fatal_error != 0);
}
@@ -685,7 +705,7 @@ multi_update::~multi_update()
{
TABLE_LIST *table;
for (table= update_tables ; table; table= table->next)
table->table->no_keyread=0;
table->table->no_keyread= table->table->no_cache= 0;
if (tmp_tables)
{