déclencheur MySQL: Comparer la valeur dans une autre table
Question
Je le déclenchement suivant (générée en utilisant PHP via mysqli) ...
DROP TRIGGER IF EXISTS post_queue_insert;
CREATE TRIGGER post_queue_insert AFTER INSERT ON posts
FOR EACH ROW BEGIN
IF (NEW.post_type != 'revision' AND NEW.post_status != 'auto-draft') THEN
INSERT INTO event_queue (action_id, action_do, action_key, action_value, action_event, action_timestamp, sync_complete, SITE_ID) VALUES (NEW.ID, 'post', NEW.post_type, NEW.post_status, 'insert', UNIX_TIMESTAMP(now()), 0, 1);
END IF;
END;
Ce que je ne peux pas comprendre comment vérifier si la valeur « post_type » existe dans une autre table et si elle n'insère pas alors il.
La solution
DROP TRIGGER IF EXISTS post_queue_insert;
CREATE TRIGGER post_queue_insert AFTER INSERT ON posts
FOR EACH ROW BEGIN
DECLARE found_it INT;
IF (NEW.post_type != 'revision' AND NEW.post_status != 'auto-draft') THEN
SELECT COUNT(1) INTO found_it FROM some_other_table
WHERE post_type = NEW.post_type;
IF found_it = 0 THEN
INSERT INTO event_queue (action_id, action_do, action_key, action_value, action_event, action_timestamp, sync_complete, SITE_ID) VALUES (NEW.ID, 'post', NEW.post_type, NEW.post_status, 'insert', UNIX_TIMESTAMP(now()), 0, 1);
END IF;
END IF;
END;
Si found_it = 0, la ligne ne contient pas de valeur NEW.post_type correspondant.
Lui donner un essai !!!
Autres conseils
DROP TRIGGER IF EXISTS post_queue_insert;
CREATE TRIGGER post_queue_insert AFTER INSERT ON posts
FOR EACH ROW BEGIN
IF ( NEW.post_type != 'revision'
AND NEW.post_status != 'auto-draft'
AND NOT EXISTS
( SELECT *
FROM other_table
WHERE post_type = NEW.post_type
)
)
THEN
INSERT INTO event_queue (action_id, action_do, action_key, action_value, action_event, action_timestamp, sync_complete, SITE_ID)
VALUES (NEW.ID, 'post', NEW.post_type, NEW.post_status, 'insert', UNIX_TIMESTAMP(now()), 0, 1);
END IF;
END;
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