Wondering how the Meta Box plugin stores field value in the database? Understanding this can help you get the field value easily and understand the returned value from
get_post_meta or helper functions.
For non-cloneable fields, the plugin stores field value in the data base in a WordPress-compatible way as following:
- If field has single value, it will be saved in single row in the post meta table.
- If field has multiple values (set by
'multiple' => truelike
image, etc.), each value will be saved in single row in the post meta table.
This way you can use
update_post_meta to update meta values and
get_post_meta to retrieve them.
For cloneable fields, cloned values are stored as a serialized array in a single row in the post meta table.
The plugin does not to store cloned values in separated rows in the database because it’s confusing that we don’t know these are values of clones, or values of the field with
'multiple' => true. To make it work for all field types and for consistency, storing cloned values in a single row of the database is a better choice.
Due to this reason, you still can use
get_post_meta function to retrieve field value from the database (WordPress automatically unserializes string and returns an array). You will get an array of all cloned values.
For normal fields, the value saved in the database is the value entered or selected by users. But for some specific fields, the values store is not as obvious as that. Please see more details in each field in the left menu, section Fields.
Although you can use
get_post_meta to retrieve meta value, it’s recommended to use helper functions to get the value and display it in the frontend. The helper function takes care of all the logic above and returns to you the needed data in a correct format.
To understand how the value is stored in the database, please use
print_r function, like this:
$value = get_post_meta( get_the_ID(), 'field_id', true ); // Last param should be 'false' if field is multiple echo '<pre>'; print_r( $value ); echo '</pre>';