［drupal］如何把database从PostgreSQL改为MySQL

1. 删除/var/www/html/sites/default/ 下的settings.php 文档，并常见同名的文件并改为write权限；

2. 如果Mysqld daemon［服务］没有启动，启动这个服务；

3. 在创建数据库之前，因为postgreSQL/MySQL 为安全考虑，不允许root用户运行，所以必须给他们建立对应的用户
    $su - postgres   or   $su - mysql 然后进入/var/lib/pgsql/ or /var/lib/mysql directory
3. 开始创建dababase/user/userpwd ;
    创建用户名和数据库：mysqladmin -u username -p create databasename；MySQL will prompt for the 'username' database password and then initial database files. Next you must login and set the access database rights:
    mysql -u username -p 
Again, you will be asked for the 'username' database password. At the MySQL prompt, enter follwing command:

  GRANT SELECT, INSERT, UPDATE, DELETE, CREATE, DROP, INDEX, ALTER
  ON databasename.*
  TO 'username'@'localhost' IDENTIFIED BY 'password';

where

 'databasename' is the name of your database
 'username@localhost' is the username of your MySQL account
 'password' is the password required for that username

Note: Unless your database user has all of the privileges listed above, you will
not be able to run Drupal.

If successful, MySQL will reply with:

  Query OK, 0 rows affected