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
=
50
where
id
=
2
;
3.删除数据
delete from 表名 [ where 条件];
delete
from
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
1
and
条件
2
and
条件
N
;
select
*
from
product
where
name
=
'Nike'
and
price
=
50
;
# or 或
select
*
from
表名
where
条件
1
or
条件
2
or
条件
N
;
select
*
from
product
where
name
=
'Nike'
or
price
>
50
;
# not 非
select
*
from
表名
where
not
条件
1
;
select
*
from
product
where
not
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
not
in
(
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 where s . teacher_id = t . id ;