zoukankan      html  css  js  c++  java
  • 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 

  • 相关阅读:
    java练习6
    java练习5
    java练习4
    java练习3
    java练习2
    java练习1
    用代码实现判断字符串的开头和结尾
    语句练习题2
    语句练习题1
    值类型和引用类型的区别
  • 原文地址:https://www.cnblogs.com/mekor/p/3550144.html
Copyright © 2011-2022 走看看