User Contributed Notes

1. Skip to note 3 content

   
   kimdcottrell
   
   
   7 years ago
   

   You must log in to vote on the helpfulness of this noteVote results for this note: 8You must log in to vote on the helpfulness of this note

   update_user_meta() will update ALL user meta of the same key UNLESS you specify a specific record out of the set that you want to replace.

   Here’s a way to do that, specifically for the instance where you have user meta that may look like this:

   +---------+----------------------+-----------------
   | user_id | meta_key             | meta_value                                                                                               |
   +---------+----------------------+-----------------
   | 862     | favorite_coffee      | {"coffee_id":10,"title":"Vietnamese Iced Coffee","type":"drip"}                                          
   | 862     | favorite_coffee      | {"coffee_id":11,"title":"Mocha","type":"espresso"}                                                       
   | 862     | favorite_coffee      | {"coffee_id":12,"title":"Just An Okay Cappuchino","type":"espresso"}

   // dummy data to better show the issue, we want to change the title of `coffee_id` 12
   $parameters = array(
       'coffee_id' => '12',
       'title' => 'A Delicious Cappuchino',
       'type' => 'espresso',
   );
   
   // try to find some `favorite_coffee` user meta 
   $previous_favorite_coffee = get_user_meta( $user_id, 'favorite_coffee', false );
   
   /**
   * First, the condition for when no favorite_coffee user meta data exists
   **/ 
   if ( empty( $previous_favorite_coffee ) ) {
       add_user_meta( $user_id, 'favorite_coffee', $parameters );
   }
   
   /**
   * Second, the condition for when some favorite_coffee user_meta data already exists
   **/
   // search recursively through records returned from get_user_meta for the record you want to replace, as identified by `coffee_id` - credit: <a href="http://php.net/manual/en/function.array-search.php#116635" rel="nofollow ugc">http://php.net/manual/en/function.array-search.php#116635</a>
   $coffee_id = array_search( $parameters['coffee_id'], array_column( $previous_favorite_coffee, 'coffee_id' ) );
   if ( false === $coffee_id ) {
       // add if the wp_usermeta meta_key[favorite_coffee] => meta_value[ $parameters[ $coffee_id ] ] pair does not exist
       add_user_meta( $user_id, 'favorite_coffee', $parameters );
   } else {
       // update if the wp_usermeta meta_key[favorite_coffee] => meta_value[ $parameters[ $coffee_id ] ] pair already exists
       update_user_meta( $user_id, 'favorite_coffee', $parameters, $previous_favorite_coffee[ $coffee_id ] );
   }

2. Skip to note 4 content

   
   Codex
   
   
   10 years ago
   

   You must log in to vote on the helpfulness of this noteVote results for this note: 3You must log in to vote on the helpfulness of this note

   how to check for errors

   $user_id = 1;
   $new_value = 'some new value';
   
   // Will return false if the previous value is the same as $new_value.
   $updated = update_user_meta( $user_id, 'some_meta_key', $new_value );
   
   // So check and make sure the stored value matches $new_value.
   if ( $new_value != get_user_meta( $user_id,  'some_meta_key', true ) ) {
   	wp_die( __( 'An error occurred', 'textdomain' ) );
   }