PDO bind unknown number of parameters? [duplicate]

Answer 1

You can build the "IN (...)" string dynamically:

$in_string = '(';
foreach ( $array_of_parameters as $parameter ) {
    $in_string .= ':' . chr($i + 97) . ','; // Get the ASCII character
}
$in_string = substr($in_string, 0, -1) . ')';

$statement = $db->prepare("SELECT blah FROM blah_table WHERE blahID IN ($in_string)");

Answer 2

Not really hacky, Loops are part of the language for looping a variable number of times.

$values = array('val1', 'val2');
$sql = 'SELECT * FROM Table Where column IN(';
$params = array();
foreach ($values as $val)
{
    $params[] = '?';
    $binds[] = $val;
}
$prep = $db->prepare($sql . join(', ', $params) . ')');
$i = 0;
foreach($binds as $bind){
   $prep->bindValue(++$i, $bind);
}
$prep->execute();

Loop over each value you need to bind, create an array of binding objects which you loop over after appending the SQL.

Answer 3

A way to do it without an explicit loop but giving specific markers rather than question marks.

$values_array = array(1, 3, 5, 7, 11);
$sql = "SELECT * 
          FROM table
         WHERE column IN (" . implode(",", array_map(function($in){return ':a'.$in;}, range(1, count($values)))) . ")";
$prep = $db->prepare($sql);
$i = 1;
foreach($values_array as $key=>$value)
{
   $prep->bindValue(':a'.$i++, $values_array[$key]);
}

This uses range to generate an array of numbers from 1 to the number of items in the array, then array_map to change those numbers to prepend them with a : and a character (in this case just a).

Only did this due to trying to debug something which used question marks and was failing. Problem turned out to be elsewhere (due to looping through the array to bind the values and having problems with bind using the reference to the variable, which was changed in each iteration of the array - hence landing up having the same value in each of the bind positions), but thought this might be useful to someone.

Answer 4

Just another shorter way of doing it.

$values = array(1, 2, 3, 4);
$sql = "SELECT * 
          FROM table
         WHERE column IN (" . join(',', array_map(function() { return '?'; }, $values)) . ")";
$db->prepare($sql);
$db->execute($values);