Filter Post By Query If the Value is Null

• mohamedmusthafac

• August 30, 2014 at 8:16 pm

I need to filter the post querying though if value is Null

Below is the code where i am passing the values dynamically by user input, so user can input all 4 fields or either any of three fields, or any of the two fields or any of the one field

So i need to query the post accordingly though if any of the field is empty also

$args = array(
    'numberposts' => -1,
    'post_type' => 'post',
    'meta_query' => array(
        'relation' => 'OR',
           array(
            'key' => 'regulation',
            'value' => $regulation,
            'compare' => '='
        ),
            array(
            'key' => 'subject_id',
            'value' => $subject_code,
            'compare' => '='
        ),
            array(
            'key' => 'department',
            'value' => $department,
            'compare' => '='
        ),
            array(
            'key' => 'categories',
            'value' => $categories,
            'compare' => '='
        ),
    )
);

For example: if the field input by the user is null then it should compare as not equal to, so how i can query if the value is not equal to “NULL” (NOT TO CHECK)

i also tried with the following example but not working

$args = array(
    'numberposts' => -1,
    'post_type' => 'post',
    'meta_query' => array(
        'relation' => 'OR',
           array(
            'key' => 'regulation',
            'value' => $regulation,
            'compare' => '='
        ),
            array(
            'key' => 'regulation',
            'value' => '',
            'compare' => '!='
        ),
            array(
            'key' => 'subject_id',
            'value' => $subject_code,
            'compare' => '='
        ),
            array(
            'key' => 'subject_id',
            'value' => '',
            'compare' => '!='
        ),
            array(
            'key' => 'department',
            'value' => $department,
            'compare' => '='
        ),
             array(
            'key' => 'department',
            'value' => '',
            'compare' => '!='
        ),
            array(
            'key' => 'categories',
            'value' => $categories,
            'compare' => '='
        ),
             array(
            'key' => 'categories',
            'value' => '',
            'compare' => '!='
        ),
    )
);

• VoiD2008

• August 31, 2014 at 1:49 am

checking for NULL value in meta_queries is:
$args = array(
‘numberposts’ => -1,
‘post_type’ => ‘post’,
‘meta_query’ => array(
‘relation’ => ‘OR’,
array(
‘key’ => ‘regulation’,
‘compare’ => ‘NOT EXISTS‘
)
)
)

it is key word for SQL IS NULL

• VoiD2008

• August 31, 2014 at 1:52 am

wp-includes/meta.php LINE 765

			if ( 'NOT EXISTS' == $meta_compare ) {
				$join[$i]  = "LEFT JOIN $meta_table";
				$join[$i] .= $i ? " AS $alias" : '';
				$join[$i] .= " ON ($primary_table.$primary_id_column = $alias.$meta_id_column AND $alias.meta_key = '$meta_key')";

				$where[$k] = ' ' . $alias . '.' . $meta_id_column . ' IS NULL';

				continue;
			}

• Nicegirl

• January 28, 2018 at 2:09 am

Here a good example for your question and answer for your problem : http://www.balitaeverywhere.com/how-meta-query-work-even-if-the-value-of-the-form-is-empty/ Dont forget to like and share the page .