$q = mysqli_query($dbc,"
SELECT *
FROM tree_tbl
WHERE
tree_code IN ( '".implode("', '", $array)."' )");
However, if your $array comes from a request you must sanitize first.
$q = mysqli_query($dbc,"
SELECT *
FROM tree_tbl
WHERE
tree_code IN ( '".implode("', '", $array)."' )");
However, if your $array comes from a request you must sanitize first.