From 196b616accbc73d212f21e2ec84353931a2f286b Mon Sep 17 00:00:00 2001 From: unknown Date: Fri, 14 Mar 2008 19:38:22 +0400 Subject: BUG#28248 - mysqldump results with MERGE ... UNION=() cannot be executed When there are no underlying tables specified for a merge table, SHOW CREATE TABLE outputs a statement that cannot be executed. The same is true for mysqldump (it generates dumps that cannot be executed). This happens because SQL parser does not accept empty UNION() clause. This patch changes the following: - it is now possible to execute CREATE/ALTER statement with empty UNION() clause. - the same as above, but still worth noting: it is now possible to remove underlying tables mapping using ALTER TABLE ... UNION=(). - SHOW CREATE TABLE does not output UNION() clause if there are no underlying tables specified for a merge table. This makes mysqldump slightly smaller. mysql-test/r/merge.result: A test case for BUG#28248. mysql-test/t/merge.test: A test case for BUG#28248. sql/ha_myisammrg.cc: Do not output UNION clause in SHOW CREATE TABLE, when there are no underlying tables defined. sql/sql_yacc.yy: Make underlying table list for MERGE engine optional. As for MERGE engine empty underlying tables list is valid, it should be valid for the parser as well. This change is mostly needed to restore dumps made by earlier MySQL versions. Also with this fix it is possible to remove underlying tables mapping by using ALTER TABLE ... UNION=(). --- mysql-test/t/merge.test | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'mysql-test/t/merge.test') diff --git a/mysql-test/t/merge.test b/mysql-test/t/merge.test index 35443987858..e5cc4d703f2 100644 --- a/mysql-test/t/merge.test +++ b/mysql-test/t/merge.test @@ -542,5 +542,18 @@ SELECT * FROM t3; DROP TABLE t1, t2, t3; +# +# BUG#28248 - mysqldump results with MERGE ... UNION=() cannot be executed +# +CREATE TABLE t1(a INT); +CREATE TABLE m1(a INT) ENGINE=MERGE; +SHOW CREATE TABLE m1; +DROP TABLE m1; +CREATE TABLE m1(a INT) ENGINE=MERGE UNION=(); +SHOW CREATE TABLE m1; +ALTER TABLE m1 UNION=(t1); +ALTER TABLE m1 UNION=(); +SHOW CREATE TABLE m1; +DROP TABLE t1, m1; --echo End of 5.0 tests -- cgit v1.2.1