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    dba_handlers

    (PHP 4 >= 4.3.0, PHP 5, PHP 7, PHP 8)

    dba_handlers — Список всех доступных обработчиков

    Описание

    dba_handlers(bool $full_info = false): array

    dba_handlers() возвращает список всех доступных в этом модуле обработчиков.

    Список параметров

    full_info

    Включает, либо выключает, вывод полной информации в результат.

    Возвращаемые значения

    Возвращает массив обработчиков баз данных. Если параметр full_info задан, как true, массив будет содержать ассоциативный массив, где ключами будут имена обработчиков, а значением информация о версии. В ином случае, массив будет индексированным массивом и содержать имена обработчиков в качестве значений.

    Замечание:

    Если используется встроенная база данных, вы увидите и cdb и cdb_make.

    Примеры

    Пример #1 Пример использования dba_handlers()

    <?php

    echo "Доступные обработчики DBA:\n";
    foreach (    dba_handlers(true) as $handler_name => $handler_version) {
    // Очищаем строки с версиями
    $handler_version = str_replace('$', '', $handler_version);
    echo     " - $handler_name: $handler_version\n";
    }

    ?>

    Вывод приведённого примера будет похож на: 

    Доступные обработчики DBA:
 - cdb: 0.75, Revision: 1.3.2.3
 - cdb_make: 0.75, Revision: 1.2.2.4
 - db2: Sleepycat Software: Berkeley DB 2.7.7: (08/20/99)
 - inifile: 1.0, Revision: 1.6.2.3
 - flatfile: 1.0, Revision: 1.5.2.4

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    User Contributed Notes 1 note

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    cbemerine at gmail dot com
    15 years ago
    A quick way to see which DBA handlers, without version numbers, that have been built into your version of MySQL on your system, use var_dump with dba_handler() as follows:

    <?php
    var_dump     ( "dba_handlers()" );
    ?>

    Many distros build in these DBA Handlers by default:
    array(5) { [0]=>  string(3) "cdb" [1]=>  string(8) "cdb_make" [2]=>  string(3) "db4" [3]=>  string(7) "inifile" [4]=>  string(8) "flatfile" }

    using print and pre tags for readability:

    array(5) {

      [0]=>

      string(3) "cdb"

      [1]=>

      string(8) "cdb_make"

      [2]=>

      string(3) "db4"

      [3]=>

      string(7) "inifile"

      [4]=>

      string(8) "flatfile"

    }

    Note there are issues with dba_insert and dba_replace without building for either GDBM or QDBM.
      Here are two sources for the list of DBA handlers: (http://www.php-editors.com/php_manual/ref.dba.html and http://dewa03.unep.org/manuals/php_manual/ref.dba.html; )

    CDBM & CDB compiles have issues with updates, you can read databases and write new database files, but you will be prevented from using dba_replace() and you may have issues with dba_insert().

    NDBM & DBM are depreciated.

    DB2, DB3 & DB4 (Berkeley DB Sleepycat Software / Oracle)  Have read online about issues with dba_replace() and db4 specifically. Make sure you test your installation for correct usage of all DBA functions.

    SDBM, TDB, TinyCDB were not listed on most of the sources I have found online.  Those DBA handlers and the names of the developers were listed on the QDBM source forge site.  How they interact with dba_replace() I do not know.  You should be aware of their existence. 

    GDBM and QDBM are the only other two DBA handlers I am aware of.  Both are reported to allow PHP's dba_replace() function to work correctly so either may be an acceptable option.  The following three restrictions of traditional DBM are not issues for either GDBM or QDBM: 1) a process can handle only one database;  2) the size of a key and a value is bounded;   3) a database file is sparse.

    DBA handler benchmark compares QDBM, GDBM, NDBM, SDBM, TDB, CDB, BDB, QDBM-BT-ASC, QDBM-BT-RND, BDB-BT-ASC, BDB-BT-RND can be found here: (http://qdbm.sourceforge.net/benchmark.pdf);

    QDBM seems to offer significant improvements in speed over the other DBA Handlers, test in your environment to verify the results.
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