如何在PHP 7中启用MySQLi扩展？?mysql

我已经在Ubuntu 14.04（Trusty Tahr）上安装了PHP 7和MySQL 5.5.47。

我已经使用以下方法检查了已安装的扩展程序：

sudo apt-cache search php7-* 它输出：

php7.0-common - Common files for packages built from the PHP source libapache2-mod-php7.0 - server-side, HTML-embedded scripting language (Apache 2 module) php7.0-cgi - server-side, HTML-embedded scripting language (CGI binary) php7.0-cli - command-line interpreter for the PHP scripting language php7.0-phpdbg - server-side, HTML-embedded scripting language (PHPDBG binary) php7.0-fpm - server-side, HTML-embedded scripting language (FPM-CGI binary) libphp7.0-embed - HTML-embedded scripting language (Embedded SAPI library) php7.0-dev - Files for PHP7.0 module development php7.0-dbg - Debug symbols for PHP7.0 php7.0-curl - CURL module for PHP php7.0-enchant - Enchant module for PHP php7.0-gd - GD module for PHP php7.0-gmp - GMP module for PHP php7.0-imap - IMAP module for PHP php7.0-interbase - Interbase module for PHP php7.0-intl - Internationalisation module for PHP php7.0-ldap - LDAP module for PHP php7.0-mcrypt - libmcrypt module for PHP php7.0-readline - readline module for PHP php7.0-odbc - ODBC module for PHP php7.0-pgsql - PostgreSQL module for PHP php7.0-pspell - pspell module for PHP php7.0-recode - recode module for PHP php7.0-snmp - SNMP module for PHP php7.0-tidy - tidy module for PHP php7.0-xmlrpc - XMLRPC-EPI module for PHP php7.0-xsl - XSL module for PHP php7.0 - server-side, HTML-embedded scripting language (metapackage) php7.0-json - JSON module for PHP php-all-dev - package depending on all supported PHP development packages php7.0-sybase - Sybase module for PHP php7.0-sqlite3 - SQLite3 module for PHP php7.0-mysql - MySQL module for PHP php7.0-opcache - Zend OpCache module for PHP php7.0-bz2 - bzip2 module for PHP 我也无法使用phpinfo（）看到MySQLi扩展。如何在PHP 7中启用/安装MySQLi扩展？

这就是为什么我不能使用phpMyAdmin的原因。它说：“缺少mysqli扩展名。”