1DROP TABLE IF EXISTS t1,t2; 2CREATE TABLE t1 (a <INT_COLUMN>, b <CHAR_COLUMN>) ENGINE=<STORAGE_ENGINE> <CUSTOM_TABLE_OPTIONS>; 3INSERT INTO t1 (a,b) VALUES (1,'a'),(2,'b'),(3,'c'),(4,'d'),(5,'e'),(10000,'foobar'); 4INSERT INTO t1 (a,b) SELECT a, b FROM t1; 5CREATE TABLE t2 (c <CHAR_COLUMN>, d <INT_COLUMN>) ENGINE=<STORAGE_ENGINE> <CUSTOM_TABLE_OPTIONS>; 6INSERT INTO t2 (c,d) SELECT b, a FROM t1; 7UPDATE IGNORE t1 SET b = 'upd1' WHERE b IS NOT NULL ORDER BY a LIMIT 1; 8SELECT a,b FROM t1; 9a b 101 a 111 upd1 1210000 foobar 1310000 foobar 142 b 152 b 163 c 173 c 184 d 194 d 205 e 215 e 22UPDATE IGNORE t1, t2 SET b = 'upd2a', c = 'upd2b' 23WHERE c < b OR a != ( SELECT 1 UNION SELECT 2 ); 24Warnings: 25Warning 1242 Subquery returns more than 1 row 26SELECT a,b FROM t1; 27a b 281 a 291 upd2a 3010000 upd2a 3110000 upd2a 322 upd2a 332 upd2a 343 upd2a 353 upd2a 364 upd2a 374 upd2a 385 upd2a 395 upd2a 40SELECT c,d FROM t2; 41c d 42upd2b 1 43upd2b 1 44upd2b 10000 45upd2b 10000 46upd2b 2 47upd2b 2 48upd2b 3 49upd2b 3 50upd2b 4 51upd2b 4 52upd2b 5 53upd2b 5 54DROP TABLE t1, t2; 55