PHP 8.4.2 Released!

Pdo\Sqlite::createCollation

(PHP 8 >= 8.4.0)

Pdo\Sqlite::createCollation Registers a user-defined function for use as a collating function in SQL statements

Beschreibung

public Pdo\Sqlite::createCollation(string $name, callable $callback): bool

This method is similar to Pdo\Sqlite::createFunction() except that it registers functions that are used to collate strings.

Parameter-Liste

name
Name of the SQL collating function to be created or redefined.
callback
Callback function that defines the behaviour of a collation. It must accept two strings and return -1, 0, or 1 if the first string sorts before, sorts identically, or sorts after the second string respectively. An internal function that behaves like this is strcmp().

This function need to be defined as:

collation(string $string1, string $string2): int

Rückgabewerte

Gibt bei Erfolg true zurück. Bei einem Fehler wird false zurückgegeben.

Beispiele

Beispiel #1 Pdo\Sqlite::createCollation() example

<?php
$db
= new Pdo\Sqlite('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";
}
?>

Das oben gezeigte Beispiel erzeugt folgende Ausgabe:

a1
a10
a2

a1
a2
a10

Siehe auch

  • Pdo\Sqlite::createFunction() - Registriert eine benutzerdefinierte Funktion zur Verwendung in SQL-Anweisungen
  • Pdo\Sqlite::createAggregate() - Registriert eine benutzerdefinierte Aggregationsfunktion zur Verwendung in SQL-Anweisungen
  • sqlite_create_function()
  • sqlite_create_aggregate()
add a note

User Contributed Notes

There are no user contributed notes for this page.
To Top