Instructions on adding the extension = php_mysqli.dll command to php. ini

For more information about. description of the extensionphp_mysqli.dll command added in ini: mysql is used as the database when php5 is configured. many people think that. add the extension = php_mysql.dll; command in ini. it is unclear why extension = php_mysqli.dll is recommended in many articles.

You only need to check the latest official php Manual, which is written as follows:

The following is a list of built-in extension libraries:

PHP 5 (as of 5.0.4) has the following changes. Added built-in: DOM, LibXML, Iconv, SimpleXML, SPL, and SQLite. The following are no longer built-in: MySQL and Overload.

The original php5 does not have these extension libraries (of course, you can also find that you do not need to add these commands when using php4). The manual also describes why php5 does not have a client library that is no longer bound to mysql:

This is partly because (there is no specific order ):

. Currently, most systems have installed client libraries.

. For the above reasons, keeping multiple versions of library files will cause confusion. For example, if you connect mod_auth_mysql to a certain version, but connect PHP to another version, and activate them in Apache at the same time, countless errors will be generated. In addition, the bound library file cannot always work well with the server version. The most obvious symptom is where to find the UNIX-domain socket file mysql. socket.

. Maintenance is a little lax, and the release version is falling behind.

. In the future, the library version is based on GPL, so there is no way to upgrade, because we cannot bind GPL-based libraries and BSD/Apache style license projects together. Therefore, having a clean PHP 5 is the best choice.

The reason why two extension libraries are activated for php during configuration is:

. To access the mysql database server using basic function operations, you must add mysql support when configuring php, that is, use the php_mysql.dll Extension Library.

. Although the php_mysql.dll Extension Library is compatible with versions later than mysql 4.1.0, it does not support the additional features provided by these versions. to use these features, you also need to use the php_mysqli.dll Extension Library.

PHP 4 (as of PHP 4.3.11): BCMath, Caledar, COM, Ctype, FTP, MySQL, ODBC, Overload, PCRE, Session, Tokenizer, WDDX, XML, and Zlib.