简答题：mysql5.5常用的语句有哪些？

简答题：mysql5.5常用的语句有哪些？

1
选择：select * from table where 范围

2
插入：insert into table(field1,field2) values(value1,value2)

3
删除：delete from table where 范围

4
更新：update table set field1=value1 where 范围

5
查找：select * from table where field1 like ’%value1%’

6
排序：select * from table order by field1,field2 [desc]

7
总数：select count as totalcount from table

8
求和：select sum(field1) as sumvalue from table

9
平均：select avg(field1) as avgvalue from table

10
最大：select max(field1) as maxvalue from table

11
最小：select min(field1) as minvalue from table

12
例：

SELECT TOP 20 * FROM table

意思是：从table中查询前 20 项的全部内容

*可以用table中的内容表示

意思是：从table中查询前 20 项"某一项"的内容

SELECT SUM(grade) as total,average(grade) as average FROM table GROUP BY class

意思是：以班级为单位，查询这个班的总成绩和平均成绩

UPDATE table SET age=age+10

意思是：将 table 中所有人的年龄增加10岁2016-03-09