增:insert into T_1(Name,Age) values (’李小争’23);
Values 中顺序要和表名中的顺序一致
查:select Name,Id from T1;
Select * from T1;//查询出所有字段
select * from T_Student where Age<30
删:delete from T_Student where Name='lxz'
从T_Student中删除Name字段等于lxz的数据
Delete from T_Student
删除T_Student中的所有数据
Delete from T_Student where Age>100 or Name=’lxz’ 或者
Delete from T_Student where Age>100 and Height>150 并且
更新:update T_Student set Age=Age+1
update T_Student set Height=180
update T_Student set Love='散步' where Age>100
select Name as 姓名, Age as 年龄 from T_Student
select MAX(age) from T_Student 查询最大年龄
select MAX(age),MIN(age) from T_Student
select MAX(age) as 最大年龄,MIN(age) as 最小年龄,AVG(age) as 平均年龄 from T_Student
select MAX(age) as 最大年龄,MIN(age) as 最小年龄,AVG(age) as 平均年龄,COUNT(*) as 总行数 from T_Student
select * from T_Student where Name like 'y%'
查询以y开头后面有若干个字符。。。
select * from T_Student where Name like '%a%'
查询含有a
select * from T_Student order by Age 按照年龄升序排列
select * from T_Student order by Age Desc 按照年龄升序排列
select * from T_Student where Name like 'y%' order by Age