Member Price deletion

When a product is deleted, the member price corresponding to this item should also be removed from the member's price list.

Delete a member's price before deleting an item

Two methods:

Program implementation: "With this, extensibility comparison, do not need to modify the table structure"

protected function _before_delete ($option)
{
$id = $option [' WHERE '] [' id ']; The ID of the item to delete
/*************** Delete the original picture *******************/
Find out the path to the original picture first
$oldLogo = $this->field (' Logo,mbig_logo,big_logo,mid_logo,sm_logo ')->find ($id);
DeleteImage ($oldLogo);

/********** Delete Member Price *******/
$mpModel =d (' Member_price ');
$mpModel->where (Array (
' goods_id ' =>array (' eq ', $id),
))->delete ();
}

MYSQL comes with a foreign key:

Extension: How do I not use code deletion, and when I delete an item, the records in the member's price list are automatically deleted?

You can use the self-contained foreign KEY constraint in MySQL to implement the "premise: only InnoDB engine support"

drop table if exists p40_member_price;
CREATE TABLE P40_member_price
(
Price Decimal (10,2) is not null comment ' member prices ',
level_id mediumint unsigned not NULL comment ' level ID ',
goods_id mediumint unsigned not NULL comment ' Product ID ',
foreign KEY (goods_id) references P40_goods (ID) on DELETE cascade,
Key level_id (level_id),
Key goods_id (goods_id)
) Engine=innodb default Charset=utf8 comment ' member Price ';

Member Price deletion