本地主机（MAMP）中的WP CLI“建立数据库连接时出错”

当我尝试使用WP CLI创建内容时出现此错误：

Error establishing a database connection. This either means that the username and password information in your `wp-config.php` file is incorrect or we can’t contact the database server at `localhost`. This could mean your host’s database server is down.

但是我可以使用以下链接打开网站：http：// localhost：8888 / projectname

任何的想法？

进入您的wp-config.php并将其更改DB_HOST为127.0.0.1而不是localhost。

感谢评论中的Craig Wayne。

对我来说，答案是将的设置更改为DB_HOST，127.0.0.1:8889而不是localhostin wp-config.php，并在MySQL设置中选中了“允许对MySQL的网络访问”框。将端口设置为MAMP Pro用于数据库的端口是我在此处其他答案中没有看到的关键缺失件。YMMV。

确保使用MAMP PHP二进制文件。您可以检查运行哪个PHP版本WP CLI。

php wp-cli.phar --info

要使用最新的MAMP PHP，您需要修改bash或zsh配置文件：

PHP_VERSION=$(ls /Applications/MAMP/bin/php/ | sort -n | tail -1)
export PATH=/Applications/MAMP/bin/php/${PHP_VERSION}/bin:$PATH

确保重新加载配置文件：

source ~/.bash_profile

确保更改正确应用：

  php wp-cli.phar --info

步骤1：检查您的mysql服务器是否正在运行步骤2：如果是，则可以使用以下方式登录到mysql：

mysql -u root -p

然后输入密码：（必须在终端上使用此命令），然后使用以下命令确保数据库存在：

show databases;
grant all privileges on database_name.* to 'root'@'localhost' identified by 'password';
flush privileges;
exit;

现在编辑wp-config.php文件并搜索

define('DB_NAME', 'db_name');
define('DB_USER', 'root');
define('DB_PASSWORD', 'password');
define('DB_HOST', 'localhost');

现在重新启动服务器，并尝试登录到您的wordpress仪表板。希望对您有所帮助。

就我而言，除了上述错误消息外，我还收到以下警告：

PHP Warning:  mysqli_real_connect(): Server sent charset (255) unknown to the client. Please, report to the developers in /var/www/html/wp-includes/wp-db.php on line 1531
Warning: mysqli_real_connect(): Server sent charset (255) unknown to the client. Please, report to the developers in /var/www/html/wp-includes/wp-db.php on line 1531
PHP Warning:  mysqli_real_connect(): (HY000/2054): Server sent charset unknown to the client. Please, report to the developers in /var/www/html/wp-includes/wp-db.php on line 1531
Warning: mysqli_real_connect(): (HY000/2054): Server sent charset unknown to the client. Please, report to the developers in /var/www/html/wp-includes/wp-db.php on line 1531
PHP Deprecated:  mysql_connect(): The mysql extension is deprecated and will be removed in the future: use mysqli or PDO instead in /var/www/html/wp-includes/wp-db.php on line 1562
Deprecated: mysql_connect(): The mysql extension is deprecated and will be removed in the future: use mysqli or PDO instead in /var/www/html/wp-includes/wp-db.php on line 1562
PHP Warning:  mysql_connect(): Server sent charset (255) unknown to the client. Please, report to the developers in /var/www/html/wp-includes/wp-db.php on line 1562
Warning: mysql_connect(): Server sent charset (255) unknown to the client. Please, report to the developers in /var/www/html/wp-includes/wp-db.php on line 1562
PHP Warning:  mysql_connect(): Server sent charset unknown to the client. Please, report to the developers in /var/www/html/wp-includes/wp-db.php on line 1562
Warning: mysql_connect(): Server sent charset unknown to the client. Please, report to the developers in /var/www/html/wp-includes/wp-db.php on line 1562

根据此问题，发生此问题是因为MySQL 8.0的默认字符集是utfmb4。

实际上，我可以通过从MySQL 5.7升级到MySQL 8.0来复制错误。

我通过导出数据库，降级到MySQL 5.7并重新导入数据解决了该问题。我还对MariaDB 10.3进行了测试，并且工作正常。

就我而言，我必须执行他的解决方案中提出的建议（https://wordpress.stackexchange.com/a/313862/172520），当然还要允许Mac（使用MAMP Pro）对MySQL进行网络访问。

其中有两个部分需要共同努力：

—您需要从切换localhost到127.0.0.1并在最后添加端口号。对我来说是127.0.0.1:3306。

端口号在Mamp的MySQL面板中。