sql，CREATE DATABASE my_database;，`，接着创建用户并赋予权限：，`sql，CREATE USER 'my_user'@'localhost' IDENTIFIED BY 'password';，GRANT ALL PRIVILEGES ON my_database.* TO 'my_user'@'localhost';，`，使用以下命令连接到新创建的数据库：，`sql，mysql -u my_user -p password my_database;，``WHERE子句来筛选满足特定条件的记录。SELECT * FROM table_name WHERE column_name = 'value';用于查找列column_name等于value的所有行。sql，SHOW VARIABLES LIKE 'datadir'; -查看数据目录，SELECT table_schema, sum(data_length + index_length) / 1024 / 1024 AS 'MB' FROM information_schema.TABLES GROUP BY table_schema; -查看各数据库占用的存储空间（单位：MB），``Powered By Z-BlogPHP 1.7.3