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).
注: However, dbm support is deprecated and you are encourged to use the Database (dbm-style) abstraction layer functions instead.
To use this functions you have to compile PHP with
support for an underlying database. See the list of supported
Databases.
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 sytem
libraries.
The function dbmopen() returns an database
identifier which is used by the other
dbm-functions.