connection default;
CREATE TABLE t1(
id	INT,
PRIMARY KEY(id)
) ENGINE=InnoDB;
INSERT INTO t1 VALUES(1), (2), (3);
BEGIN;
SELECT * FROM t1 WHERE id = 1 LOCK IN SHARE MODE;
connect  con1,localhost,root,,;
BEGIN;
SELECT * FROM t1 WHERE id = 2 LOCK IN SHARE MODE;
connect  con2,localhost,root,,;
BEGIN;
SELECT * FROM t1 WHERE id = 2 LOCK IN SHARE MODE;
SELECT * FROM t1 WHERE id = 1 FOR UPDATE;
connection default;
SELECT * FROM t1 WHERE id = 2 FOR UPDATE;
connection con2;
disconnect con1;
ROLLBACK;
disconnect con2;
connection default;
ROLLBACK;
DROP TABLE t1;