Question

FYI. ended up going with PDO solution as this was simpler.

I’m trying to add a single method to handle all queries to the database. I want the queries to use parameter binding. How do I handle a variable amount of function parameters in mysqli_stmt_bind_param()?

This post here led me to understand the pros of parameter binding.

Here is my example code..where I am currently stuck at is marked.

INPUT PARAMETERS

  $query = "INSERT INTO b0 VALUES (?, ?, ?)"
  $par_arr = {'bookmark', 'http://www.bookmark.com', 'tag'}

PROTOTYPE CODE

  protected static function query($query, $par_arr)
    {
    if($statement=mysqli_prepare(one::$db, $query) 
      {
      mysqli_stmt_bind_param($statement, "s", ...variable amount of parameters...);<----how should this be handled?
      ...

Answer 1

Update 2: If you experience any further problems with this code, then you should probably follow this advice and use PDO instead.

This is how you should be using call_user_func_array ^[docs]:

protected static function query($query, $types, $values) {
    if($statement = mysqli_prepare(one::$db, $query) {
        $parameters = array_merge(array($statement, $types), $values);    
        call_user_func_array('mysqli_stmt_bind_param', $parameters);
        // ...
    }
}

where $types is a string indicating the type of each value, as described in the mysqli_stmt_bind_param documentation (call_user_func_array is even mentioned there).

---

Update: It seems it is not that easy after all, and you have to create references to the values first:

 foreach($values as $k => $v) {
     $values[$k] = &$v;
 }

 $parameters = array_merge(array($statement, $types), $values);
 call_user_func_array('mysqli_stmt_bind_param', $parameters);
 // ...

---

call_user_func_array is for user defined functions per php.net

No it’s not. The first parameter is of type callback, and the documentation says (emphasis mine):

A PHP function is passed by its name as a string. Any built-in or user-defined function can be used, except language constructs such as: array(), echo(), empty(), eval(), exit(), isset(), list(), print() or unset().

Next remark:

is just used to simplify syntax for passing arrays to user defined functions

Have you had a look at the examples? Each element of the array you pass to call_user_func_array will be passed as argument to the function you specify. Arrays are the only way to have a collection of values of variable size.