Query to get result by Title or Meta along with tax_query parameter

Question

If I use the following code, it is working:

new WP_Query([
            'post_status'    => 'publish',
            'post_type'      => "some_custom_post_type",
            'orderby'        => 'DATE',
            'order'          => 'DESC',
            'facetwp'        => true,
            'posts_per_page' => 15,
            'paged'          => $paged,
            '_meta_or_title'=> $_POST['query'],
            'meta_query'    => array(
                'relation'      => 'OR',
                array(
                    'key'       => 'some_meta_value1',
                    'value'     => $_POST['query'],
                    'compare'   => 'LIKE',
                ),
                array(
                    'key'       => 'some_meta_value2',
                    'value'     => $_POST['query'],
                    'compare'   => 'LIKE',
                ),
            )
        ])

But whenever I use tax_quey, it is not working, e.g.:

new WP_Query([
                'post_status'    => 'publish',
                'post_type'      => "some_custom_post_type",
                'orderby'        => 'DATE',
                'order'          => 'DESC',
                'facetwp'        => true,
                'posts_per_page' => 15,
                'paged'          => $paged,
                'tax_query'      => [[
                   'taxonomy' => 'some_taxonomy',
                   'terms'    => ['some_terms_slug'],
                   'field'    => 'slug',
                   'operator' => 'IN',
                ]],
                '_meta_or_title'=> $_POST['query'],
                'meta_query'    => array(
                    'relation'      => 'OR',
                    array(
                        'key'       => 'some_meta_value1',
                        'value'     => $_POST['query'],
                        'compare'   => 'LIKE',
                    ),
                    array(
                        'key'       => 'some_meta_value2',
                        'value'     => $_POST['query'],
                        'compare'   => 'LIKE',
                    ),
                )
            ])

Meta query modifier code

add_action( 'pre_get_posts', function( $q )
{
    if( $title = $q->get( '_meta_or_title' ) )
    {
        add_filter( 'get_meta_sql', function( $sql ) use ( $title )
        {
            global $wpdb;

            // Only run once:
            static $nr = 0; 
            if( 0 != $nr++ ) return $sql;

            // Modified WHERE
            $sql['where'] = sprintf(
                " AND ( %s OR %s ) ",
                $wpdb->prepare( "{$wpdb->posts}.post_title like '%%%s%%'", $title),
                mb_substr( $sql['where'], 5, mb_strlen( $sql['where'] ) )
            );
            return $sql;
        });
    }
});

I need to filter out the data Meta Values or Title, Any suggestions? Thanks in advance

Answer 1

From the documentation:

apply_filters_ref_array( 'get_meta_sql', string[] $sql, array $queries, string $type, string $primary_table, string $primary_id_column, object $context )

Filters the meta query’s generated SQL.

and

$type

(string) Type of meta. Possible values include but are not limited to 'post', 'comment', 'blog', 'term', and 'user'.

So because a hook like the one above can run multiple times on a page, which means your filter/closure could be called multiple times for the same posts query (i.e. WP_Query call), then you should do something like if ( 'post' === $type ) { modify the $sql['where'] } to modify the WHERE only if the meta type is exactly post.

And basically after I tested your code, I noticed that the conditional if( 0 != $nr++ ) return $sql; skipped modifying the post meta query and instead modified a term meta query, which means when the hook called your closure for the 1st time, it was for a term meta query.

Hence, that explains why the "whenever I use tax_query, it is not working".

How can you fix the issue

1. Change the add_filter( 'get_meta_sql', function( $sql ) use ( $title ) to add_filter( 'get_meta_sql', function( $sql, $queries, $type ) use ( $title ).

2. Change the return $sql; }); to return $sql; }, 10, 3); (i.e. let the above closure accepts 3 parameters).

3. Then change the if( 0 != $nr++ ) return $sql; to if( 'post' !== $type || 0 != $nr++ ) return $sql;

Additional Code

You could use get_meta_sql alone without having to use pre_get_posts to add a filter for get_meta_sql, like so:

add_filter( 'get_meta_sql', 'my_get_meta_sql', 10, 6 );
function my_get_meta_sql( $sql, $queries, $type, $primary_table, $primary_id_column, $context ) {
    // Check that it's a post meta type and that the main query object is an instance of WP_Query.
    if ( 'post' === $type && $context instanceof WP_Query &&
        // And check that the _meta_or_title arg is set.
        ( $title = $context->get( '_meta_or_title' ) )
    ) {
        global $wpdb;

        $sql['where'] = 'YOUR CODE..';
    }

    return $sql;
}