Bug #26242 UPDATE with subquery and triggers failing with cluster tables

In certain cases AFTER UPDATE/DELETE triggers on NDB tables that referenced
subject table didn't see the results of operation which caused invocation
of those triggers. In other words AFTER trigger invoked as result of update
(or deletion) of particular row saw version of this row before update (or
deletion).

The problem occured because NDB handler in those cases postponed actual
update/delete operations to be able to perform them later as one batch.

This fix solves the problem by disabling this optimization for particular
operation if subject table has AFTER trigger for this operation defined.
To achieve this we introduce two new flags for handler::extra() method:
HA_EXTRA_DELETE_CANNOT_BATCH and HA_EXTRA_UPDATE_CANNOT_BATCH.
These are called if there exists AFTER DELETE/UPDATE triggers during a
statement that potentially can generate calls to delete_row()/update_row().
This includes multi_delete/multi_update statements as well as insert statements
that do delete/update as part of an ON DUPLICATE statement.

1 files changed, 108 insertions, 0 deletions

diff --git a/mysql-test/t/ndb_trigger.test b/mysql-test/t/ndb_trigger.test
index 2521ef17842..25b079cfe7c 100644
--- a/mysql-test/t/ndb_trigger.test
+++ b/mysql-test/t/ndb_trigger.test
@@ -89,4 +89,112 @@ select * from t2 order by op, a, b;
 
 drop tables t1, t2, t3;
 
+# Test for bug#26242
+# Verify that AFTER UPDATE/DELETE triggers are executed
+# after the change has actually taken place
+
+CREATE TABLE t1 (
+  id INT NOT NULL PRIMARY KEY,
+  xy INT
+) ENGINE=ndbcluster;
+
+INSERT INTO t1 VALUES (1, 0);
+
+DELIMITER //;
+CREATE TRIGGER t1_update AFTER UPDATE ON t1 FOR EACH ROW BEGIN REPLACE INTO t2 SELECT * FROM t1 WHERE t1.id = NEW.id; END //
+DELIMITER ;//
+
+CREATE TABLE t2 (
+  id INT NOT NULL PRIMARY KEY,
+  xy INT
+) ENGINE=ndbcluster;
+
+INSERT INTO t2 VALUES (2, 0);
+
+CREATE TABLE t3 (id INT NOT NULL PRIMARY KEY) ENGINE=ndbcluster;
+
+INSERT INTO t3 VALUES (1);
+
+CREATE TABLE t4 LIKE t1;
+
+DELIMITER //;
+CREATE TRIGGER t4_update AFTER UPDATE ON t4 FOR EACH ROW BEGIN REPLACE INTO t5 SELECT * FROM t4 WHERE t4.id = NEW.id; END //
+DELIMITER ;//
+
+CREATE TABLE t5 LIKE t2;
+
+UPDATE t1 SET xy = 3 WHERE id = 1;
+SELECT xy FROM t1 where id = 1;
+SELECT xy FROM t2 where id = 1;
+
+UPDATE t1 SET xy  = 4 WHERE id IN (SELECT id FROM t3 WHERE id = 1);
+SELECT xy FROM t1 where id = 1;
+SELECT xy FROM t2 where id = 1;
+
+INSERT INTO t4 SELECT * FROM t1;
+INSERT INTO t5 SELECT * FROM t2;
+UPDATE t1,t4 SET t1.xy = 3, t4.xy = 3 WHERE t1.id = 1 AND t4.id = 1;
+SELECT xy FROM t1 where id = 1;
+SELECT xy FROM t2 where id = 1;
+SELECT xy FROM t4 where id = 1;
+SELECT xy FROM t5 where id = 1;
+
+UPDATE t1,t4 SET t1.xy = 4, t4.xy = 4 WHERE t1.id IN (SELECT id FROM t3 WHERE id = 1) AND t4.id IN (SELECT id FROM t3 WHERE id = 1);
+SELECT xy FROM t1 where id = 1;
+SELECT xy FROM t2 where id = 1;
+SELECT xy FROM t4 where id = 1;
+SELECT xy FROM t5 where id = 1;
+
+INSERT INTO t1 VALUES (1,0) ON DUPLICATE KEY UPDATE xy = 5;
+SELECT xy FROM t1 where id = 1;
+SELECT xy FROM t2 where id = 1;
+
+DROP TRIGGER t1_update;
+DROP TRIGGER t4_update;
+
+DELIMITER //;
+CREATE TRIGGER t1_delete AFTER DELETE ON t1 FOR EACH ROW BEGIN REPLACE INTO t2 SELECT * FROM t1 WHERE t1.id > 4; END //
+DELIMITER ;//
+
+DELIMITER //;
+CREATE TRIGGER t4_delete AFTER DELETE ON t4 FOR EACH ROW BEGIN REPLACE INTO t5 SELECT * FROM t4 WHERE t4.id > 4; END //
+DELIMITER ;//
+
+INSERT INTO t1 VALUES (5, 0),(6,0);
+INSERT INTO t2 VALUES (5, 1),(6,1);
+INSERT INTO t3 VALUES (5);
+SELECT * FROM t1 order by id;
+SELECT * FROM t2 order by id;
+DELETE FROM t1 WHERE id IN (SELECT id FROM t3 WHERE id = 5);
+SELECT * FROM t1 order by id;
+SELECT * FROM t2 order by id;
+
+INSERT INTO t1 VALUES (5,0);
+UPDATE t2 SET xy = 1 WHERE id = 6;
+TRUNCATE t4;
+INSERT INTO t4 SELECT * FROM t1;
+TRUNCATE t5;
+INSERT INTO t5 SELECT * FROM t2;
+SELECT * FROM t1 order by id;
+SELECT * FROM t2 order by id;
+SELECT * FROM t4 order by id;
+SELECT * FROM t5 order by id;
+DELETE FROM t1,t4 USING t1,t3,t4 WHERE t1.id IN (SELECT id FROM t3 WHERE id = 5) AND t4.id IN (SELECT id FROM t3 WHERE id = 5);
+SELECT * FROM t1 order by id;
+SELECT * FROM t2 order by id;
+SELECT * FROM t4 order by id;
+SELECT * FROM t5 order by id;
+
+INSERT INTO t1 VALUES (5, 0);
+REPLACE INTO t2 VALUES (6,1);
+SELECT * FROM t1 order by id;
+SELECT * FROM t2 order by id;
+REPLACE INTO t1 VALUES (5, 1);
+SELECT * FROM t1 order by id;
+SELECT * FROM t2 order by id;
+
+DROP TRIGGER t1_delete;
+DROP TRIGGER t4_delete;
+DROP TABLE t1, t2, t3, t4, t5;
+
 --echo End of 5.0 tests