global $wpdb;

/* grab meta value, it is assumed you know the post id ($id) in question */
$dot_number = get_post_meta( $id, \'dot_number\', true );

/* grab all rows with matching value in \'dot_number\' column */
$matches_query = $wpdb->get_results(
    "SELECT * FROM " . $wpdb->prefix . "csadata " .
    "WHERE dot_number = " . $dot_number, ARRAY_A
);

// do something with query result, usually iterate over it and display something