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| author | Dmitry Shulga <dmitry.shulga@mariadb.com> | 2021-07-14 22:12:15 +0700 |
|---|---|---|
| committer | Dmitry Shulga <dmitry.shulga@mariadb.com> | 2021-07-14 22:12:15 +0700 |
| commit | 655496a8d483366ed62e2a116402d42a169901c2 (patch) | |
| tree | a8102e1946470c6b644415e781de6bf955745758 | |
| parent | 04369f9cee4e2ce7562d42344cd59683b5fbb8ae (diff) | |
| download | mariadb-git-bb-10.6-MDEV-26145.tar.gz | |
MDEV-26145: Incorrect metadata is sent on running query with union in PS modebb-10.6-MDEV-26145
Test cases like the following one produce different result sets if it's run
with and without th option --ps-protocol.
CREATE TABLE t1(a INT);
--enable_metadata
(SELECT MAX(a) FROM t1) UNION (SELECT MAX(a) FROM t1);
--disable_metadata
DROP TABLE t1;
Result sets differ in metadata for the query
(SELECT MAX(a) FROM t1) UNION (SELECT MAX(a) FROM t1);
The reason for different content of query metadata is that for queries
with union the items being created on JOIN preparing phase is placed into
item_list from SELECT_LEX_UNIT whereas for queries without union item_list
from SELECT_LEX is used instead.
| -rw-r--r-- | mysql-test/main/ps.result | 13 | ||||
| -rw-r--r-- | mysql-test/main/ps.test | 13 | ||||
| -rw-r--r-- | sql/sql_prepare.cc | 8 |
3 files changed, 33 insertions, 1 deletions
diff --git a/mysql-test/main/ps.result b/mysql-test/main/ps.result index eb17def9a4b..c0080cb55d2 100644 --- a/mysql-test/main/ps.result +++ b/mysql-test/main/ps.result @@ -5615,3 +5615,16 @@ DROP USER user1@localhost; # # End of 10.4 tests # +# +# MDEV-26145: Incorrect metadata is sent on running query with union in PS mode +# +CREATE TABLE t1(a INT); +(SELECT MAX(a) FROM t1) UNION (SELECT MAX(a) FROM t1); +Catalog Database Table Table_alias Column Column_alias Type Length Max length Is_null Flags Decimals Charsetnr +def MAX(a) MAX(a) 3 11 0 Y 32768 0 63 +MAX(a) +NULL +DROP TABLE t1; +# +# End of 10.6 tests +# diff --git a/mysql-test/main/ps.test b/mysql-test/main/ps.test index e5285022efd..6cdc8de2415 100644 --- a/mysql-test/main/ps.test +++ b/mysql-test/main/ps.test @@ -5054,3 +5054,16 @@ DROP USER user1@localhost; --echo # --echo # End of 10.4 tests --echo # + +--echo # +--echo # MDEV-26145: Incorrect metadata is sent on running query with union in PS mode +--echo # +CREATE TABLE t1(a INT); +--enable_metadata +(SELECT MAX(a) FROM t1) UNION (SELECT MAX(a) FROM t1); +--disable_metadata +DROP TABLE t1; + +--echo # +--echo # End of 10.6 tests +--echo # diff --git a/sql/sql_prepare.cc b/sql/sql_prepare.cc index 2f5470db123..5b4e0698de4 100644 --- a/sql/sql_prepare.cc +++ b/sql/sql_prepare.cc @@ -1609,7 +1609,13 @@ static int mysql_test_select(Prepared_statement *stmt, if (!lex->describe && !thd->lex->analyze_stmt && !stmt->is_sql_prepare()) { /* Make copy of item list, as change_columns may change it */ - List<Item> fields(lex->first_select_lex()->item_list); + + SELECT_LEX_UNIT* master_unit= lex->first_select_lex()->master_unit(); + bool is_union_op= + master_unit->is_unit_op() || master_unit->fake_select_lex; + + List<Item> fields(is_union_op ? unit->item_list : + lex->first_select_lex()->item_list); /* Change columns if a procedure like analyse() */ if (unit->last_procedure && unit->last_procedure->change_columns(thd, fields)) |