dynamic variables binding in mysqli bind_param

问题:

when i try to below code it give me a warning

mysqli_stmt::bind_param(): Number of elements in type definition string doesn't match number of bind variables

$stmt = $mysqli->prepare('SELECT * FROM users WHERE lname = ? AND fname = ?');
    $type = "ss";
    $param = array("Maq","bool");
    $params[] = &$type;
    $params[] = &$param;

    call_user_func_array( array($stmt, 'bind_param'), $params );

i really don't know why its happening i read a lot of same title questions in stackoverflow but some has comma separated types or need more type but in my case i think its proper but why i am keep getting warnings?

回答1:

$stmt = $mysqli->prepare('SELECT * FROM users WHERE lname = ? AND fname = ?');
$stmt->bind_param('ss', $param[0], $param[1]);
$stmt->execute();

//other version
$stmt = $mysqli->prepare('SELECT * FROM users WHERE lname = ? AND fname = ?');
$type = "ss";
$names = array("Maq", "bool");
$params = array(&$type, &$names[0], &$names[1]);

call_user_func_array(array($stmt, 'bind_param'), $params);

回答2:

This is a late answer, I hope will help someone.

It's a part of my mysqliLayer class, so I extracted needed variables.

// establish mysqli connection
$conn = new mysqli(.....); 
$tableName = 'users';
// Types to bind
$type = 'isss';
$fields = ['id','name', 'email', 'created'];
$values = [1, 'angel', '[e-mail]', '2018-1-12'];

$sql = "INSERT INTO " . $tableName . " (" . join(',', $fields) . ") VALUES (?,?,?,?)";

$stmt = $conn->prepare($sql);
// Using ...token introduced in php v.5.6 instead of call_user_func_array
// This way references can be omitted, like for each value in array
$stmt->bind_param($type, ...$values);

$stmt->execute();

$stmt->close();