1、建庫：CREATE DATABASE IF NOT EXISTS 庫名 DEFAULT CHARSET utf8;或CREATE DATABASE 表名  

建表（例）：

CREATE TABLE IF NOT EXISTS cs_user(
id INT PRIMARY KEY AUTO_INCREMENT,
username VARCHAR(20) NOT NULL UNIQUE,
PASSWORD VARCHAR(20) NOT NULL,
gender VARCHAR(5) NOT NULL,
age INT NOT NULL
);

2、增：INSERT INTO cs_user(username,PASSWORD,gender,age)VALUES("一","123456","男",17),("二","123456","男",19);

刪：DELETE FROM cs_user WHERE username="一";刪除某一條資料         DROP TABLE cs_user;刪除表

查：SELECT * FROM cs_user;查詢所有資料      SELECT * FROM cs_user WHERE username="一";查詢某條資料

改：UPDATE cs_user SET PASSWORD="111" WHERE username="一";

3、表關聯查詢：

#內連線w.id和a.site_id的數相同的一行資料合併
SELECT * FROM websites w INNER JOIN access_log a ON w.id=a.site_id;
#左連線 left join...on 是指內連線後左表多餘的部分的資料
SELECT * FROM websites w LEFT JOIN access_log a ON w.id=a.site_id;
#右連線 left join...on
SELECT * FROM websites w RIGHT JOIN access_log a ON w.id=a.site_id;
#全連線=左連線 union 右連線
#這裡是內連線+左連線+右連線 union去重，union all不去重
SELECT * FROM websites w LEFT JOIN access_log a ON w.id=a.site_id
UNION
SELECT * FROM websites w RIGHT JOIN access_log a ON w.id=a.site_id;

4、子查詢

SELECT * FROM teacherinfo WHERE YEAR(Birthday) IN (SELECT YEAR(Birthday) FROM teacherinfo WHERE Name='夏老師');查詢所有與夏老師同一年出生的教師資訊