5.5.15

SQLite3::createCollation

(PHP 5 >= 5.3.11)

SQLite3::createCollationRegisters a PHP function for use as an SQL collating function

Description

public bool SQLite3::createCollation ( string $name , callable $callback )

Registers a PHP function or user-defined function for use as a collating function within SQL statements.

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.

Return Values

Returns TRUE on success or FALSE on failure.

Examples

Example #1 SQLite3::createCollation() example

Register the PHP function strnatcmp() as a collating sequence in the SQLite3 database.

<?php

$db 
= new SQLite3(":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->createCollation('NATURAL_CMP''strnatcmp');

$defaultSort $db->query("SELECT col1 FROM test ORDER BY col1");
$naturalSort $db->query("SELECT col1 FROM test ORDER BY col1 COLLATE NATURAL_CMP");

echo 
"default:\n";
while (
$row $defaultSort->fetchArray()){
    echo 
$row['col1'], "\n";
}

echo 
"\nnatural:\n";
while (
$row $naturalSort->fetchArray()){
    echo 
$row['col1'], "\n";
}

$db->close();

?>

The above example will output:


default:
a1
a10
a2

natural:
a1
a2
a10

See Also

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