CakePHP 2.x CookBook Chinese Version Chapter 7 Model - Deleting Data_PHP Tutorial

Delete data

CakePHP’s model class provides several methods for deleting records from the database.

delete

delete(int $id = null, boolean $cascade = true);

Delete record by $id. By default, records that are dependent on the deleted record are also deleted.

For example, to delete a User record that is related to many Recipe records (User ‘hasMany’ or ‘hasAndBelongsToMany’ Recipes):

If $cascade is set to true, the related Recipe record is also deleted (the model's dependent-value is set to true).

If $cascade is set to false, the Recipe record will still be retained after the User is deleted.

If the database supports foreign keys and cascade deletion, it will be relied on before CakePHP's cascade. One of the benefits of using the cascading feature of Model:delete() is that it allows you to use behavior and model callbacks:

1 $this->Comment->delete($this->request->data('Comment.id'));

You can hook custom logic to the deletion process using beforeDelete and afterDelete that exist in both models and behaviors. See callback methods for more information.

deleteAll

deleteAll(mixed $conditions, $cascade = true, $callbacks = false)

Basically the same as delete() except that deleteAll() will delete all records that match the provided criteria. The $conditions array will be provided as a SQL fragment or array.

conditions Conditions to match

cascade logical value, set to true, when deleting, records with dependencies will be deleted at the same time.

callbacks logical value, run callback

Returns True on success and False on failure.

Example:

1 // The conditions used for deletion are the same as find()

2 $this->Comment->deleteAll(array('Comment.spam' => true), false);

If deleted with callbacks and/or cascades, the relevant rows will be found and deleted. This often results in multiple queries being issued.

Annotations

When the delete condition executes successfully but no records match, deleteAll() will return true even if no records are deleted.

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