connect  con1,localhost,root,,;
connect  con2,localhost,root,,;
connection con1;
disconnect con1;
connection con2;
DROP TABLE IF EXISTS t1;
CREATE TABLE t1 (n INT);
INSERT INTO t1 VALUES (1),(2),(3);
SELECT * FROM t1;
n
1
2
3
DROP TABLE t1;
connection default;
disconnect con2;
connection default;
SELECT GET_LOCK("dangling", 0);
GET_LOCK("dangling", 0)
1
connect con1, localhost, root,,;
connection con1;
SELECT GET_LOCK('dangling', 3600);;
connection default;
disconnect con1;
connect con1, localhost, root,,;
SELECT GET_LOCK('dangling', 3600);;
connection default;
SELECT RELEASE_LOCK('dangling');
RELEASE_LOCK('dangling')
1
connection con1;
GET_LOCK('dangling', 3600)
1
connection default;
disconnect con1;