基础SQL语句

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