ejemplo de disparador de mysql

Ejemplo 1: disparador en sintaxis mysql

CREATE TRIGGER trigger_name
{BEFORE | AFTER} {INSERT | UPDATE| DELETE }
ON table_name FOR EACH ROW
trigger_body;

Ejemplo 2: ejemplo de disparador de mysql

-- The following statement creates an AFTER UPDATE trigger on the sales table:

DELIMITER $$

CREATE TRIGGER after_sales_update
AFTER UPDATE
ON sales FOR EACH ROW
BEGIN
    IF OLD.quantity <> new.quantity THEN
        INSERT INTO SalesChanges(salesId,beforeQuantity, afterQuantity)
        VALUES(old.id, old.quantity, new.quantity);
    END IF;
END$$

DELIMITER ;

Ejemplo 3: disparador en mysql

CREATE TRIGGER Product_Details_tr 
BEFORE INSERT ON Product_Details 
FOR EACH ROW 
SET NEW.User_ID = CURRENT_USER();

Ejemplo 4: mysql create trigger

CREATE
    TRIGGER `event_name` BEFORE/AFTER INSERT/UPDATE/DELETE
    ON `database`.`table`
    FOR EACH ROW BEGIN
		-- trigger body
		-- this code is applied to every 
		-- inserted/updated/deleted row
    END;
    
CREATE
	TRIGGER `blog_after_insert` AFTER INSERT 
	ON `blog` 
	FOR EACH ROW BEGIN
	
		IF NEW.deleted THEN
			SET @changetype="DELETE";
		ELSE
			SET @changetype="NEW";
		END IF;
    
		INSERT INTO audit (blog_id, changetype) VALUES (NEW.id, @changetype);
		
    END$$

Ejemplo 5: activadores de mysql

DELIMITER $$

CREATE TRIGGER before_workcenters_insert
BEFORE INSERT
ON WorkCenters FOR EACH ROW
BEGIN
    DECLARE rowcount INT;
    
    SELECT COUNT(*) 
    INTO rowcount
    FROM WorkCenterStats;
    
    IF rowcount > 0 THEN
        UPDATE WorkCenterStats
        SET totalCapacity = totalCapacity + new.capacity;
    ELSE
        INSERT INTO WorkCenterStats(totalCapacity)
        VALUES(new.capacity);
    END IF; 

END $$

DELIMITER ;

---

---

Utiliza Nuestro Buscador