CREATE TABLE t1 (f1 INTEGER PRIMARY KEY) ENGINE=InnoDB;
INSERT INTO t1 VALUES (1),(2);
INSERT INTO t1 VALUES (3),(4);
SELECT COUNT(*) = 4 FROM t1;
COUNT(*) = 4
1
SELECT COUNT(*) = 4 FROM t1;
COUNT(*) = 4
1
DROP TABLE t1;
CREATE TABLE t1 (f1 INTEGER, KEY (f1)) ENGINE=InnoDB;
INSERT INTO t1 VALUES (1),(1);
INSERT INTO t1 VALUES (2),(2);
SELECT COUNT(*) = 4 FROM t1;
COUNT(*) = 4
1
SELECT COUNT(*) = 4 FROM t1;
COUNT(*) = 4
1
DROP TABLE t1;
CREATE TABLE t1 (f1 INTEGER PRIMARY KEY) ENGINE=InnoDB;
INSERT INTO t1 VALUES (1), (2), (3), (4), (5), (6), (7), (8), (9), (1);
ERROR 23000: Duplicate entry '1' for key 'PRIMARY'
SELECT COUNT(*) = 0 FROM t1;
COUNT(*) = 0
1
SELECT COUNT(*) = 0 FROM t1;
COUNT(*) = 0
1
DROP TABLE t1;
CREATE TABLE t1 (f1 INTEGER PRIMARY KEY) ENGINE=InnoDB;
SET AUTOCOMMIT = OFF;
START TRANSACTION;
INSERT INTO t1 VALUES (1), (2);
SET AUTOCOMMIT = OFF;
START TRANSACTION;
INSERT INTO t1 VALUES (2), (1);
COMMIT;
COMMIT;
ERROR 40001: Deadlock found when trying to get lock; try restarting transaction
ROLLBACK;
INSERT INTO t1 VALUES (1), (2);
ERROR 23000: Duplicate entry '1' for key 'PRIMARY'
DROP TABLE t1;
CREATE TABLE t1 (f1 INTEGER PRIMARY KEY) ENGINE=InnoDB;
START TRANSACTION;
INSERT INTO t1 VALUES (1), (2);
START TRANSACTION;
INSERT INTO t1 VALUES (2), (1);
ROLLBACK;
COMMIT;
SELECT COUNT(*) = 2 FROM t1;
COUNT(*) = 2
1
SELECT COUNT(*) = 2 FROM t1;
COUNT(*) = 2
1
DROP TABLE t1;