PHP Mysqli extension: Using IN keyword in a prepared statement

Question

I'm doing some queries into MySQL database using MySQLi extension in PHP. I need to do a query like this:

SELECT col1, col2 FROM mytable WHERE id IN (2, 4, 6);

This is a concrete example of the query, but the number of ids inside the parenthesis after the IN keyword will vary. Since I want to use the mysqli->prepare() function (prepared statement) I would do it like this:

$statement->prepare("SELECT col1, col2 FROM mytable WHERE id IN (?)");
$statement->bind_pararm("s".... something)

I'm not sure what to put in the bind param function, since i cant know how many IDs will actually be queried for. I couldn't find any examples how to use IN keyword inside prepared statements.

Answer 1

If you prepare your statement once you need it, you could create the placeholders like

join(",", array_fill(0, count($ids) , "?"))

or something.