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author | Igor Babaev <igor@askmonty.org> | 2021-06-21 16:15:07 -0700 |
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committer | Igor Babaev <igor@askmonty.org> | 2021-06-21 16:21:17 -0700 |
commit | cc0bd8431f9a2b252697afab78e039b8cd294d01 (patch) | |
tree | 352d0781050a1806a2cb430d1ffb77e6945da832 | |
parent | 773a07b65517327add6348c045cee14bdf489fe0 (diff) | |
download | mariadb-git-cc0bd8431f9a2b252697afab78e039b8cd294d01.tar.gz |
MDEV-25679 Wrong result selecting from simple view with LIMIT and ORDER BY
This bug affected queries with views / derived_tables / CTEs whose
specifications were of the form
(SELECT ... LIMIT <n>) ORDER BY ...
Units representing such specifications contains one SELECT_LEX structure
for (SELECT ... LIMIT <n>) and additionally SELECT_LEX structure for
fake_select_lex. This fact should have been taken into account in the
function mysql_derived_fill().
This patch has to be applied to 10.2 and 10.3 only.
-rw-r--r-- | mysql-test/r/derived_view.result | 21 | ||||
-rw-r--r-- | mysql-test/t/derived_view.test | 17 | ||||
-rw-r--r-- | sql/sql_derived.cc | 2 |
3 files changed, 39 insertions, 1 deletions
diff --git a/mysql-test/r/derived_view.result b/mysql-test/r/derived_view.result index fe25feb5a38..d8ee508f5db 100644 --- a/mysql-test/r/derived_view.result +++ b/mysql-test/r/derived_view.result @@ -3436,3 +3436,24 @@ Warnings: Note 1003 select `test`.`t1`.`pk` AS `pk`,`test`.`t1`.`a` AS `a`,3 AS `d`,`test`.`t2`.`b` AS `b`,`test`.`t3`.`c` AS `c` from `test`.`t1` join `test`.`t2` join `test`.`t3` where `test`.`t1`.`a` = 3 and `test`.`t1`.`pk` <= 2 drop view v1; drop table t1,t2,t3; +# +# MDEV-25679: view / derived table defined as ordered select with LIMIT +# +create table t1 (a int); +insert into t1 values (3), (7), (1); +create view v1 as (select a from t1 limit 2) order by a desc; +(select a from t1 limit 2) order by a desc; +a +7 +3 +select * from v1; +a +7 +3 +select * from ((select a from t1 limit 2) order by a desc) dt; +a +7 +3 +drop view v1; +drop table t1; +# End of 10.2 tests diff --git a/mysql-test/t/derived_view.test b/mysql-test/t/derived_view.test index 46d6a7805ca..89ada40e84c 100644 --- a/mysql-test/t/derived_view.test +++ b/mysql-test/t/derived_view.test @@ -2249,3 +2249,20 @@ eval explain extended $q; drop view v1; drop table t1,t2,t3; + +--echo # +--echo # MDEV-25679: view / derived table defined as ordered select with LIMIT +--echo # + +create table t1 (a int); +insert into t1 values (3), (7), (1); + +create view v1 as (select a from t1 limit 2) order by a desc; +(select a from t1 limit 2) order by a desc; +select * from v1; +select * from ((select a from t1 limit 2) order by a desc) dt; + +drop view v1; +drop table t1; + +--echo # End of 10.2 tests diff --git a/sql/sql_derived.cc b/sql/sql_derived.cc index 3ab93840d80..632baf4bc5b 100644 --- a/sql/sql_derived.cc +++ b/sql/sql_derived.cc @@ -1091,7 +1091,7 @@ bool mysql_derived_fill(THD *thd, LEX *lex, TABLE_LIST *derived) res= derived->fill_recursive(thd); } } - else if (unit->is_union()) + else if (unit->is_union() || unit->fake_select_lex) { // execute union without clean up res= unit->exec(); |