MYSQL_常用语句

1.插入数据
insert into表名(列名1,列名2,列名..) values(值1,值2,值...);

insert into product(name, price, pic_path) values('Nike',500,'uploads/3245.jpg');

2.更新数据
update 表名set列名1=值1,列名2=值2[where条件];

update product set name='LiNing', price=50where id=2;

3.删除数据
deletefrom表名[where条件];

deletefrom product where id=2;

4.查询所有数据 
select*from表名;select*from product;

5.查询部份列
select列名1,列名2,列名N from表名;

select name, price from product;

6.条件查询
# 比较 =, <, >, <=, >=, !=

select*from表名where列名=值;

select*from product where id=2;

# and 与

select*from表名where条件1and条件2and条件N;

select*from product where name='Nike'and price=50;

# or 或

select*from表名where条件1or条件2or条件N;

select*from product where name='Nike'or price>50;

# not 非

select*from表名wherenot条件1;

select*from product wherenot name='Nike';

#in 枚举

select*from表名where列名in(值1,值2,值N);

select*from product where id in(2,3,4,10);

select*from product where id notin(2,3,4,10);

#like 模糊查询

select*from表名where列名 like '%值%';

select*from product where name like '%Li%';

#between...and... 范围查询

select*from表名where列名 between 值and值;

select*from order where created between '2010-01-01'and'2011-01-01';

7.查询排序
select*from表名 order by列名排序方式;

#排序方式: asc(升序，默认)，desc(降序)

select*from product order by created desc;

8.限制查询结果数量
select*from表名 limit 开始记录数,结果数量;select*from product limit 5;

select*from product limit 2,5;

9.聚合函数
# count 总记录数

select count(列名)from student;

select count(id)from student;

# sum 总共

select sum(列名)from student;

select sum(age)from student;

# avg 平均值

select avg(列名)from student;

select avg(age)as avg_age from student;

# max 最大值

select max(列名)from student;

select max(age)from student;

# min 最小值

select min(列名)from student;

select min(age)from student;

10.子查询
select name from student where age<(select avg(age)from student );

select*from product where id in(select id from order );

11.连接查询
select s.username as stu_name, t.name as te_name from student s, teacher t wheres.teacher_id=t.id;