mysql -u root -p
数据库-表-数据1、分号结束2、符号都是英文状态下的查看数据库show databases; 创建数据库create database student;删除数据库drop database student;进入数据库use student;查看表show tables;"创建表" 123 字段 数据类型 约束条件, 主键create table stu( sno int(11) primary key, name varchar(20), sex varchar(10) default "男", age int(11) default 10);删除表drop table stu;查看表结构desc stu;数据的增删改查查询:select tname,rsex from stu ;select * from student where sname like "%李%" ;select * from teacher where tname = "李诚" and tsex = "男";select * from teacher where tname = "王萍" or tsex = "男";增加:insert into stu values("张三","男",12),("李四","男",12);insert into stu(name,age) values("李四",12);删除delete from student ;修改update student set sname = "张三" ;修改字段名称 用 as
SQL功能 动词
数据查询 select数据操纵 insert,update,delete关系运算:>,=,<,>=,>=,!=(<>)
范围运算:between...and;空判断:is null,is not null; IN判断:in,not in,exists(复杂查询)模糊查询:like,not like逻辑运算 and与 or或 not非