delete_metadata( string $meta_type, int $object_id, string $meta_key, mixed $meta_value = '', bool $delete_all = false ): bool
Deletes metadata for the specified object.
Parameters
-
$meta_type
string Required -
Type of object metadata is for. Accepts
'post'
,'comment'
,'term'
,'user'
, or any other object type with an associated meta table. -
$object_id
int Required -
ID of the object metadata is for.
-
$meta_key
string Required -
Metadata key.
-
$meta_value
mixed Optional -
Metadata value. Must be serializable if non-scalar.
If specified, only delete metadata entries with this value.
Otherwise, delete all entries with the specified meta_key.
Passnull
,false
, or an empty string to skip this check.
(For backward compatibility, it is not possible to pass an empty string to delete those entries with an empty string for a value.)Default:
''
-
$delete_all
bool Optional -
If true, delete matching metadata entries for all objects, ignoring the specified object_id. Otherwise, only delete matching metadata entries for the specified object_id.
Default:
false
Return
bool True on successful delete, false on failure.
Source
File: wp-includes/meta.php
.
View all references
function delete_metadata( $meta_type, $object_id, $meta_key, $meta_value = '', $delete_all = false ) {
global $wpdb;
if ( ! $meta_type || ! $meta_key || ! is_numeric( $object_id ) && ! $delete_all ) {
return false;
}
$object_id = absint( $object_id );
if ( ! $object_id && ! $delete_all ) {
return false;
}
$table = _get_meta_table( $meta_type );
if ( ! $table ) {
return false;
}
$type_column = sanitize_key( $meta_type . '_id' );
$id_column = ( 'user' === $meta_type ) ? 'umeta_id' : 'meta_id';
// expected_slashed ($meta_key)
$meta_key = wp_unslash( $meta_key );
$meta_value = wp_unslash( $meta_value );
/**
* Short-circuits deleting metadata of a specific type.
*
* The dynamic portion of the hook name, `$meta_type`, refers to the meta object type
* (post, comment, term, user, or any other type with an associated meta table).
* Returning a non-null value will effectively short-circuit the function.
*
* Possible hook names include:
*
* - `delete_post_metadata`
* - `delete_comment_metadata`
* - `delete_term_metadata`
* - `delete_user_metadata`
*
* @since 3.1.0
*
* @param null|bool $delete Whether to allow metadata deletion of the given type.
* @param int $object_id ID of the object metadata is for.
* @param string $meta_key Metadata key.
* @param mixed $meta_value Metadata value. Must be serializable if non-scalar.
* @param bool $delete_all Whether to delete the matching metadata entries
* for all objects, ignoring the specified $object_id.
* Default false.
*/
$check = apply_filters( "delete_{$meta_type}_metadata", null, $object_id, $meta_key, $meta_value, $delete_all );
if ( null !== $check ) {
return (bool) $check;
}
$_meta_value = $meta_value;
$meta_value = maybe_serialize( $meta_value );
$query = $wpdb->prepare( "SELECT $id_column FROM $table WHERE meta_key = %s", $meta_key );
if ( ! $delete_all ) {
$query .= $wpdb->prepare( " AND $type_column = %d", $object_id );
}
if ( '' !== $meta_value && null !== $meta_value && false !== $meta_value ) {
$query .= $wpdb->prepare( ' AND meta_value = %s', $meta_value );
}
$meta_ids = $wpdb->get_col( $query );
if ( ! count( $meta_ids ) ) {
return false;
}
if ( $delete_all ) {
if ( '' !== $meta_value && null !== $meta_value && false !== $meta_value ) {
$object_ids = $wpdb->get_col( $wpdb->prepare( "SELECT $type_column FROM $table WHERE meta_key = %s AND meta_value = %s", $meta_key, $meta_value ) );
} else {
$object_ids = $wpdb->get_col( $wpdb->prepare( "SELECT $type_column FROM $table WHERE meta_key = %s", $meta_key ) );
}
}
/**
* Fires immediately before deleting metadata of a specific type.
*
* The dynamic portion of the hook name, `$meta_type`, refers to the meta object type
* (post, comment, term, user, or any other type with an associated meta table).
*
* Possible hook names include:
*
* - `delete_post_meta`
* - `delete_comment_meta`
* - `delete_term_meta`
* - `delete_user_meta`
*
* @since 3.1.0
*
* @param string[] $meta_ids An array of metadata entry IDs to delete.
* @param int $object_id ID of the object metadata is for.
* @param string $meta_key Metadata key.
* @param mixed $_meta_value Metadata value.
*/
do_action( "delete_{$meta_type}_meta", $meta_ids, $object_id, $meta_key, $_meta_value );
// Old-style action.
if ( 'post' === $meta_type ) {
/**
* Fires immediately before deleting metadata for a post.
*
* @since 2.9.0
*
* @param string[] $meta_ids An array of metadata entry IDs to delete.
*/
do_action( 'delete_postmeta', $meta_ids );
}
$query = "DELETE FROM $table WHERE $id_column IN( " . implode( ',', $meta_ids ) . ' )';
$count = $wpdb->query( $query );
if ( ! $count ) {
return false;
}
if ( $delete_all ) {
$data = (array) $object_ids;
} else {
$data = array( $object_id );
}
wp_cache_delete_multiple( $data, $meta_type . '_meta' );
/**
* Fires immediately after deleting metadata of a specific type.
*
* The dynamic portion of the hook name, `$meta_type`, refers to the meta object type
* (post, comment, term, user, or any other type with an associated meta table).
*
* Possible hook names include:
*
* - `deleted_post_meta`
* - `deleted_comment_meta`
* - `deleted_term_meta`
* - `deleted_user_meta`
*
* @since 2.9.0
*
* @param string[] $meta_ids An array of metadata entry IDs to delete.
* @param int $object_id ID of the object metadata is for.
* @param string $meta_key Metadata key.
* @param mixed $_meta_value Metadata value.
*/
do_action( "deleted_{$meta_type}_meta", $meta_ids, $object_id, $meta_key, $_meta_value );
// Old-style action.
if ( 'post' === $meta_type ) {
/**
* Fires immediately after deleting metadata for a post.
*
* @since 2.9.0
*
* @param string[] $meta_ids An array of metadata entry IDs to delete.
*/
do_action( 'deleted_postmeta', $meta_ids );
}
return true;
}
Hooks
-
do_action( 'deleted_postmeta',
string[] $meta_ids ) -
Fires immediately after deleting metadata for a post.
-
do_action( "deleted_{$meta_type}_meta",
string[] $meta_ids ,int $object_id ,string $meta_key ,mixed $_meta_value ) -
Fires immediately after deleting metadata of a specific type.
-
do_action( 'delete_postmeta',
string[] $meta_ids ) -
Fires immediately before deleting metadata for a post.
-
do_action( "delete_{$meta_type}_meta",
string[] $meta_ids ,int $object_id ,string $meta_key ,mixed $_meta_value ) -
Fires immediately before deleting metadata of a specific type.
-
apply_filters( "delete_{$meta_type}_metadata",
null|bool $delete ,int $object_id ,string $meta_key ,mixed $meta_value ,bool $delete_all ) -
Short-circuits deleting metadata of a specific type.
Changelog
Version | Description |
---|---|
2.9.0 | Introduced. |
User Contributed Notes
You must log in before being able to contribute a note or feedback.
Be VERY careful when using this function to delete a specific key-value pair. As stated, providing an empty string for
$meta_value
will cause the check to be skipped entirely, resulting in all keys being deleted!To avoid accidentally deleting ALL key instances, use a short-circuit check: