Avoid duplicate entry into MySQL Database
by Dinesh[ Edit ] 2013-08-03 12:42:10
First step would be to set a unique key on the table:
ALTER TABLE thetable ADD UNIQUE INDEX(pageid, name);
Then you have to decide what you want to do when there's a duplicate. Should you:
ignore it?
INSERT IGNORE INTO thetable (pageid, name) VALUES (1, "foo"), (1, "foo");
Overwrite the previously entered record?
INSERT INTO thetable (pageid, name, somefield)
VALUES (1, "foo", "first")
ON DUPLICATE KEY UPDATE (somefield = 'first')
INSERT INTO thetable (pageid, name, somefield)
VALUES (1, "foo", "second")
ON DUPLICATE KEY UPDATE (somefield = 'second')
Update some counter?
INSERT INTO thetable (pageid, name)
VALUES (1, "foo"), (1, "foo")
ON DUPLICATE KEY UPDATE (pagecount = pagecount + 1)
