PHP - update con condiciones diferentes

"UPDATE $dbTabla13

SET meta_value = $cantidad WHERE post_id = $prod_id AND 	meta_key = '_stock',

SET meta_value = $precio WHERE post_id = $prod_id AND 	meta_key = '_regular_price',

SET meta_value = $precio WHERE post_id = $prod_id AND 	meta_key = '_price'";

$query  = "UPDATE $dbTabla13 SET meta_value = $cantidad WHERE post_id = $prod_id AND meta_key = '_stock';",

$query .= "UPDATE $dbTabla13 SET meta_value = $precio WHERE post_id = $prod_id AND (meta_key = '_regular_price' OR meta_key = '_price')",

mysqli_query($conexion, $query);