SQLite3::createCollation

(PHP 5 >= 5.3.11)

SQLite3::createCollation — Registers a PHP function for use as an SQL collating function

说明

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.

参数

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.

返回值

成功时返回 TRUE ，或者在失败时返回 FALSE 。

范例

Example #1 SQLite3::createCollation() example

  <?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 ();

 ?>

以上例程会输出：

default:
a1
a10
a2natural:
a1
a2
a10

参见

The SQLite collation documentation: » http://sqlite.org/datatype3.html#collation