XXII. DBM Functions [deprecated]

Introduction

These functions allow you to store records stored in a dbm-style database. This type of database (supported by the Berkeley DB, GDBM, and some system libraries, as well as a built-in flatfile library) stores key/value pairs (as opposed to the full-blown records supported by relational databases).

Note: However, dbm support is deprecated and you are encouraged to use the Database (dbm-style) abstraction layer functions instead.

Requirements

To use this functions you have to compile PHP with support for an underlying database. See the list of supported Databases.

Installation

In order to use these functions, you must compile PHP with dbm support by using the --with-db option. In addition you must ensure support for an underlying database or you can use some system libraries.

Runtime Configuration

This extension has no configuration directives defined in php.ini.

Resource Types

The function dbmopen() returns an database identifier which is used by the other dbm-functions.

Predefined Constants

This extension has no constants defined.

Examples

Example 1. DBM example


<?php

$dbm = dbmopen("lastseen", "w");
if (dbmexists($dbm, $userid)) {
    $last_seen = dbmfetch($dbm, $userid);
} else {
    dbminsert($dbm, $userid, time());
}
do_stuff();
dbmreplace($dbm, $userid, time());
dbmclose($dbm);

?>

Table of Contents
dblist -- Describes the DBM-compatible library being used
dbmclose -- Closes a dbm database
dbmdelete -- Deletes the value for a key from a DBM database
dbmexists -- Tells if a value exists for a key in a DBM database
dbmfetch -- Fetches a value for a key from a DBM database
dbmfirstkey -- Retrieves the first key from a DBM database
dbminsert -- Inserts a value for a key in a DBM database
dbmnextkey -- Retrieves the next key from a DBM database
dbmopen -- Opens a DBM database
dbmreplace -- Replaces the value for a key in a DBM database