# Shop Supplier



DROP TRIGGER IF EXISTS before_insert_Shop_Supplier;
DROP TRIGGER IF EXISTS before_update_Shop_Supplier;


DELIMITER //
CREATE TRIGGER before_insert_Shop_Supplier
BEFORE INSERT ON Shop_Supplier
FOR EACH ROW
BEGIN
	IF NEW.created_on <=> NULL THEN
		SET NEW.created_on = NOW();
	END IF;
    IF NEW.created_by <=> NULL THEN
		SET NEW.created_by = CURRENT_USER();
	END IF;
END //
DELIMITER ;


DELIMITER //
CREATE TRIGGER before_update_Shop_Supplier
BEFORE UPDATE ON Shop_Supplier
FOR EACH ROW
BEGIN
	IF OLD.id_change_set <=> NEW.id_change_set THEN
		SIGNAL SQLSTATE '45000'
        SET MESSAGE_TEXT = 'New change Set ID must be provided.';
    END IF;
    
    INSERT INTO Shop_Supplier_Audit (
		id_supplier,
        name_field,
        value_prev,
        value_new,
        id_change_set
    )
	# Changed name_company
	SELECT NEW.id_supplier, 'name_company', OLD.name_company, NEW.name_company, NEW.id_change_set
		WHERE NOT OLD.name_company <=> NEW.name_company
    UNION
	# Changed name_contact
	SELECT NEW.id_supplier, 'name_contact', OLD.name_contact, NEW.name_contact, NEW.id_change_set
		WHERE NOT OLD.name_contact <=> NEW.name_contact
    UNION
	# Changed department_contact
	SELECT NEW.id_supplier, 'department_contact', OLD.department_contact, NEW.department_contact, NEW.id_change_set
		WHERE NOT OLD.department_contact <=> NEW.department_contact
    UNION
	# Changed id_address
	SELECT NEW.id_supplier, 'id_address', OLD.id_address, NEW.id_address, NEW.id_change_set
		WHERE NOT OLD.id_address <=> NEW.id_address
    UNION
	# Changed phone_number
	SELECT NEW.id_supplier, 'phone_number', OLD.phone_number, NEW.phone_number, NEW.id_change_set
		WHERE NOT OLD.phone_number <=> NEW.phone_number
    UNION
	# Changed fax
	SELECT NEW.id_supplier, 'fax', OLD.fax, NEW.fax, NEW.id_change_set
		WHERE NOT OLD.fax <=> NEW.fax
    UNION
	# Changed email
	SELECT NEW.id_supplier, 'email', OLD.email, NEW.email, NEW.id_change_set
		WHERE NOT OLD.email <=> NEW.email
    UNION
	# Changed website
	SELECT NEW.id_supplier, 'website', OLD.website, NEW.website, NEW.id_change_set
		WHERE NOT OLD.website <=> NEW.website
    UNION
	# Changed id_currency
	SELECT NEW.id_supplier, 'id_currency', OLD.id_currency, NEW.id_currency, NEW.id_change_set
		WHERE NOT OLD.id_currency <=> NEW.id_currency
    ;
END //
DELIMITER ;