(PHP 5 >= 5.3.11, PHP 7, PHP 8)
SQLite3::createCollation — Registers a PHP function for use as an SQL collating function
Registers a PHP function or user-defined function for use as a collating function within SQL statements.
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 values 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:
Returns true
on success or false
on failure.
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