In MySQL server, I want to do a trigger that checks when a row inserted, if the row has the previous value in column A than the previous row, it should delete it.
Im a little forgetful on how to check this correctly so if someone could lend a hand, thank you.
Best I got:
USE database;
DELIMITER $$
CREATE TRIGGER checkrow BEFORE INSERT ON table6 FOR EACH ROW
if inserted.column1 == select column1 from table6 order by id desc limit 1 then
delete inserted.column1
But after that...no clue what to do.
USE database;
DELIMITER $$
CREATE TRIGGER checkrow BEFORE INSERT ON table6 FOR EACH ROW
if inserted.sha1(column1) == select sha1(column1) from table6 order by id desc limit 1 then
delete inserted.column1;
end if
I don't think you can delete the record to be inserted. There must be a way to cancel it, perhaps by throwing an exception (signal).
Well how is the best way I can do that?
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