PDO::sqliteCreateCollation

Registers a User Defined Function for use as a collating function in SQL statements

&reftitle.description; public `bool` `PDO::sqliteCreateCollation` `string` `name` `callable` `callback` &warn.experimental.func;
&reftitle.parameters;

`name`

- Name of the SQL collating function to be created or redefined.

`callback`

- The name of a PHP function or user-defined function to apply as a callback, defining the behavior of the collation. It should accept two strings and return as strcmp() does, i.e. it should return -1, 1, or 0 if the first string sorts before, sorts after, or is equal to the second.

  This function need to be defined as: `int```collation`` `string` `string1` `string` `string2`

&reftitle.returnvalues;

&return.success;

&reftitle.examples;

### `PDO::sqliteCreateCollation` example

    <?php
    $db = new PDO('sqlite::memory:');
    $db->exec("CREATE TABLE test (col1 string)");
    $db->exec("INSERT INTO test VALUES ('a1')");
    $db->exec("INSERT INTO test VALUES ('a10')");
    $db->exec("INSERT INTO test VALUES ('a2')");

    $db->sqliteCreateCollation('NATURAL_CMP', 'strnatcmp');
    foreach ($db->query("SELECT col1 FROM test ORDER BY col1") as $row) {
      echo $row['col1'] . "\n";
    }
    echo "\n";
    foreach ($db->query("SELECT col1 FROM test ORDER BY col1 COLLATE NATURAL_CMP") as $row) {
      echo $row['col1'] . "\n";
    }
    ?>

&example.outputs;

    a1
    a10
    a2

    a1
    a2
    a10