问题
This is how I'm binding my params:
$Con = mysqli_connect(...);
$Statement = mysqli_stmt_init($Con);
mysqli_stmt_prepare($Statement,"select * from users where name=? and email=?");
mysqli_stmt_bind_param("s",$Username);
mysqli_stmt_bind_param("s",$Email); <-- it fails here
But it works fine in the other case when I replace the 2 calls to mysqli_stmt_bind_param with:
mysql_stmt_bind_param("ss",$Username,$Email)
The problem is that I have an array of params; I have to bind them one by one coz I don't know the number of params
回答1:
A bit offtopic but I find it important enough.
A very recent user comment in the manual page for mysql_stmt_bind_param contains the exact answer to this very question.
You see, this site, although encourage laziness, not always answer your question better than good old google and manual can.
回答2:
Your approach does not work because the right way to use the mysqli_stmt_bind_param is precisely follow:
mysql_stmt_bind_param("ss",$Username,$Email)
refs: http://php.net/manual/en/mysqli-stmt.bind-param.php
to know the number of parameters makes a count() array.
回答3:
MySQLi's statement binding really isn't suited to variable numbers of parameters.
I highly recommend switching to PDO
$stmt = $pdo->prepare('select * from users where name=? and email=?');
$stmt->execute($numericArrayOfParameters);
来源：https://stackoverflow.com/questions/7980140/how-to-bind-param-multiple-times-with-mysqli