Início / dba / Perguntas / 8416
Accepted
EddyR
Asked: 2011-11-27 01:20:35 +0800 CST

Gatilho do MySQL: compare o valor em outra tabela

  • 772

Eu tenho o seguinte gatilho (gerado usando 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;

O que não consigo descobrir é como verificar se o valor 'post_type' existe em outra tabela e, se não, inseri-lo.

?

mysql trigger

2 respostas

  1. Best Answer
    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;

    Se found_it = 0, a linha não contém um valor correspondente a NEW.post_type.

    De uma chance !!!

    • 4 
  2. 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;
    • 2

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