在介绍这些SQL语言之前，先罗列一下mysql的常用数据类型和数据类型修饰，供查询参考后面的带数字表示此类型的字段长度数值型：TINYINT1，SMALLINT2，MEDIUMINT3 (字段定义会丢失,数据会保留) mysql>ALTER TABLE students RENAME TO stu;mysql>RENAME TABLE stu TO students;添加一个外键约束ALTER TABLE students ADD FOREIGN KEY foreign _cid (CID) REFERENCES course (CID);创建索引CREATE INDEX index_name ON TABLE (col_name[(length)] [ASC|DESC]) [USING {BTREE|HASH}];删除索引DROP INDEX index_name ON TBNAME;查看表状态:SHOW STATUS LIKE 'TBNAME';查看表的索引:SHOW INDEXES FROM TBNAME;DML----Data Manipulation Language 数据操纵语言如insert,delete,update,select(插入、删除、修改、检索)插入修改数据#如果每个字段都有值，不需要写字段名称,每组值用,隔开mysql>INSERT INTO tb_name (col1,col2) VALUES ('STRING',NUM),('STRING',NUM);mysql>INSERT INTO tb_name SET col1='string',col2='string';mysql>INSERT INTO tb_name (col1,col2,col3) SELECT...;EXAMPLE:mysql>INSERT INTO students (Name,Gender,teacher) VALUE ('lujunyi','M','mage'),('wusong','M','zhuima');mysql>INSERT INTO students SET,Gender='M',tearcher='zhuima';更新数据mysql>UPDATE tb_name SET column=value WHERE column=value;mysql>UPDATE students SET Course='mysql' WHERE;#查询年龄大于平均年龄的数据MySQL（Linux）
MySQL 9.6.0是面向Linux平台的2026年创新版本，核心架构迎来重大革新。其将外键约束与级联操作从InnoDB引擎层上移至SQL层，确保所有数据变更均被完整记录至Binlog，彻底解决了CDC（变更数据捕获）与主从复制中的数据不一致难题。此外，该版本引入container_aware启动选项以原生适配容器环境，并对审计日志进行了组件化重构，为追求极致数据一致性与云原生体验的开发者提供了全新选择。
下载mysql>SELECT * FROM students WHERE Age > (SELECT AVG(Age) FROM students);#在FROM中使用子查询mysql>SELECT Name,Age FROM (SELECT * FROM students WHERE CID IN (2,3)) AS t WHERE Age>20;#联合查询mysql>(SELECT Name,Age FROM students) UNION (SELECT Tname,Age FROM tutors);创建视图CREATE VIEW VIEW_NAME AS SELECT....
DCL----Data Control Language 数据库控制语言如grant,deny,revoke等，只有管理员才有这样的权限。
创建用户mysql>CREATE USER 'USERNAME'@'HOST' IDENTIFIED BY 'PASSWORD'删除用户mysql>DROP USER 'USERNAME'@'HOSHOST支持通配符_:任意单个字符%:任意多个字符授权mysql>GRANT pri1,pri2...ON DB_NAME.TB_NAME TO 'USERNAME'@'HOST' [IDENTIFIED BY 'PASSWORD']取消授权mysql>REVOKE pri1,pri2...ON DB_NAME.TB_NAME FROM 'USERNAME'@'HOST';查看授权mysql>SHOW GRANTS FOR 'USERNAME'@'HOST';EXAMPLE:mysql>CREATE USER 'lujunyi'@'%' IDENTIFIED BY '123456';mysql>SHOW GRANTS FOR 'lujunyi'@'%';mysql>GRANT ALL PRIVILEGES ON testdb.* TO 'lujunyi'@'%';本文出自 “lustlost-迷失在欲望之中” 博客，虚拟主机，香港服务器，请务必保留此出处，美国空间