Question

(Very useful when querying DB).
If I have a multy dim array

 [['id'=>1],['id'=>2],['id'=>34],['id'=>67]]

and what I want is [1,2,34,67]

I know how to do it in code, just asking if there is a built in way in PHP (or may be in PDO) to do this.

Answer 1

I think you need PDO::FETCH_COLUMN mode in fetchAll, which returns only a single column as array:

<?php
$sth = $dbh->prepare("SELECT name, colour FROM fruit");
$sth->execute();

/* Fetch all of the values of the first column */
$result = $sth->fetchAll(PDO::FETCH_COLUMN, 0);
var_dump($result);
?>

From the manual:

To return an array consisting of all values of a single column from the result set, specify PDO::FETCH_COLUMN. You can specify which column you want with the column-index parameter.