wp query sort on meta code example
Example: get post order by meta value int
$defaults = array(
'numberposts' => -1,
'post_type' => 'agent_listing',
'meta_key' => 'oepl_order_no',
'orderby' => 'meta_value_num',
'order' => 'ASC',
'suppress_filters' => false
);
'orderby' => 'meta_value_num', // for int field
'orderby' => 'meta_value', // text field