一共有三个表表pic
id picName uploader shenhe 表pic记录的是某一组图片的组名,上传者,是否审核(true/false)表picFile
id parentId picFile 表picFile中的parentId对应表pic中的id,picFile记录的是图片存放路径(多张图片可能同属一个图片分组)表down
id picFile downloader down_time表down记录的是具体某张图片的下载信息,字段picFile 等于表picFile 中的字段picFile现在要列出某一个上传者(uploader)上传的所有被下载过的图片(该图片肯定是通过了审核的,也就是shenhe=true),该怎么写查询语句呢?
id picName uploader shenhe 表pic记录的是某一组图片的组名,上传者,是否审核(true/false)表picFile
id parentId picFile 表picFile中的parentId对应表pic中的id,picFile记录的是图片存放路径(多张图片可能同属一个图片分组)表down
id picFile downloader down_time表down记录的是具体某张图片的下载信息,字段picFile 等于表picFile 中的字段picFile现在要列出某一个上传者(uploader)上传的所有被下载过的图片(该图片肯定是通过了审核的,也就是shenhe=true),该怎么写查询语句呢?
inner join picfile m on p.id=m.parentId and p.shenhe='true'
inner join down n on m.picFile=n.picFile
select p.* from pic p inner join picfile m on p.id=m.parentId inner join down n on m.picFile=n.picFile
where p.shenhe='true'
并且,没有地方加比如uploader='xxx'这样的语句的地方啊
select p.* from pic p inner join picfile m on p.id=m.parentId inner join down n on m.picFile=n.picFile
where p.shenhe="true"
from pic a , picfile b , down c
where a.id = b.parentId and b.picFile = c.picFile and a.uploader = 'XXXXXX'select a.uploader , a.picName , c.picFile
from pic a , picfile b , down c
where a.id = b.parentId and b.picFile = c.picFile and a.uploader = 'XXXXXX'
from pic a , picfile b , down c
where a.id = b.parentId and b.picFile = c.picFile and a.uploader = 'XXXXXX' and a.shenhe = 'true'select a.uploader , a.picName , c.picFile
from pic a , picfile b , down c
where a.id = b.parentId and b.picFile = c.picFile and a.uploader = 'XXXXXX' and a.shenhe = 'true'
Select * from a left outer join b on a.id=b.id and a.id=2是错的
Select * from a left outer join b on a.id=b.id 才可以,后面的条件可以在这个结果上面再筛选。
SELECT c.* from
(pic a inner join picFile b on a.id=b.parentId)
left join down c on b.picFile=c.picFile
where uploader='张三' and shenhe='true'
inner join picFile t1 on t1.parentId=t0.id
inner join down t2 on t2.picFile=t1.picFile
那加distinct select distinct ..... from ....
--先参考下面取重复记录的示例,因为不知道你的具体的情况,示例之后的内容为猜测你的意思书写的SQL.--按某一字段分组取最大(小)值所在行的数据
--(爱新觉罗.毓华(十八年风雨,守得冰山雪莲花开) 2007-10-23于浙江杭州)
/*
数据如下:
name val memo
a 2 a2(a的第二个值)
a 1 a1--a的第一个值
a 3 a3:a的第三个值
b 1 b1--b的第一个值
b 3 b3:b的第三个值
b 2 b2b2b2b2
b 4 b4b4
b 5 b5b5b5b5b5
*/
--创建表并插入数据:
create table tb(name varchar(10),val int,memo varchar(20))
insert into tb values('a', 2, 'a2(a的第二个值)')
insert into tb values('a', 1, 'a1--a的第一个值')
insert into tb values('a', 3, 'a3:a的第三个值')
insert into tb values('b', 1, 'b1--b的第一个值')
insert into tb values('b', 3, 'b3:b的第三个值')
insert into tb values('b', 2, 'b2b2b2b2')
insert into tb values('b', 4, 'b4b4')
insert into tb values('b', 5, 'b5b5b5b5b5')
go--一、按name分组取val最大的值所在行的数据。
--方法1:
select a.* from tb a where val = (select max(val) from tb where name = a.name) order by a.name
--方法2:
select a.* from tb a where not exists(select 1 from tb where name = a.name and val > a.val)
--方法3:
select a.* from tb a,(select name,max(val) val from tb group by name) b where a.name = b.name and a.val = b.val order by a.name
--方法4:
select a.* from tb a inner join (select name , max(val) val from tb group by name) b on a.name = b.name and a.val = b.val order by a.name
--方法5
select a.* from tb a where 1 > (select count(*) from tb where name = a.name and val > a.val ) order by a.name
/*
name val memo
---------- ----------- --------------------
a 3 a3:a的第三个值
b 5 b5b5b5b5b5
*/--二、按name分组取val最小的值所在行的数据。
--方法1:
select a.* from tb a where val = (select min(val) from tb where name = a.name) order by a.name
--方法2:
select a.* from tb a where not exists(select 1 from tb where name = a.name and val < a.val)
--方法3:
select a.* from tb a,(select name,min(val) val from tb group by name) b where a.name = b.name and a.val = b.val order by a.name
--方法4:
select a.* from tb a inner join (select name , min(val) val from tb group by name) b on a.name = b.name and a.val = b.val order by a.name
--方法5
select a.* from tb a where 1 > (select count(*) from tb where name = a.name and val < a.val) order by a.name
/*
name val memo
---------- ----------- --------------------
a 1 a1--a的第一个值
b 1 b1--b的第一个值
*/--三、按name分组取第一次出现的行所在的数据。
select a.* from tb a where val = (select top 1 val from tb where name = a.name) order by a.name
/*
name val memo
---------- ----------- --------------------
a 2 a2(a的第二个值)
b 1 b1--b的第一个值
*/--四、按name分组随机取一条数据。
select a.* from tb a where val = (select top 1 val from tb where name = a.name order by newid()) order by a.name
/*
name val memo
---------- ----------- --------------------
a 1 a1--a的第一个值
b 5 b5b5b5b5b5
*/--五、按name分组取最小的两个(N个)val
select a.* from tb a where 2 > (select count(*) from tb where name = a.name and val < a.val ) order by a.name,a.val
select a.* from tb a where val in (select top 2 val from tb where name=a.name order by val) order by a.name,a.val
select a.* from tb a where exists (select count(*) from tb where name = a.name and val < a.val having Count(*) < 2) order by a.name,a.val
/*
name val memo
---------- ----------- --------------------
a 1 a1--a的第一个值
a 2 a2(a的第二个值)
b 1 b1--b的第一个值
b 2 b2b2b2b2
*/--六、按name分组取最大的两个(N个)val
select a.* from tb a where 2 > (select count(*) from tb where name = a.name and val > a.val ) order by a.name,a.val
select a.* from tb a where val in (select top 2 val from tb where name=a.name order by val desc) order by a.name,a.val
select a.* from tb a where exists (select count(*) from tb where name = a.name and val > a.val having Count(*) < 2) order by a.name , a.val
/*
name val memo
---------- ----------- --------------------
a 2 a2(a的第二个值)
a 3 a3:a的第三个值
b 4 b4b4
b 5 b5b5b5b5b5
*/
--七,如果整行数据有重复,所有的列都相同。
/*
数据如下:
name val memo
a 2 a2(a的第二个值)
a 1 a1--a的第一个值
a 1 a1--a的第一个值
a 3 a3:a的第三个值
a 3 a3:a的第三个值
b 1 b1--b的第一个值
b 3 b3:b的第三个值
b 2 b2b2b2b2
b 4 b4b4
b 5 b5b5b5b5b5
*/
--在sql server 2000中只能用一个临时表来解决,生成一个自增列,先对val取最大或最小,然后再通过自增列来取数据。
--创建表并插入数据:
create table tb(name varchar(10),val int,memo varchar(20))
insert into tb values('a', 2, 'a2(a的第二个值)')
insert into tb values('a', 1, 'a1--a的第一个值')
insert into tb values('a', 1, 'a1--a的第一个值')
insert into tb values('a', 3, 'a3:a的第三个值')
insert into tb values('a', 3, 'a3:a的第三个值')
insert into tb values('b', 1, 'b1--b的第一个值')
insert into tb values('b', 3, 'b3:b的第三个值')
insert into tb values('b', 2, 'b2b2b2b2')
insert into tb values('b', 4, 'b4b4')
insert into tb values('b', 5, 'b5b5b5b5b5')
goselect * , px = identity(int,1,1) into tmp from tbselect m.name,m.val,m.memo from
(
select t.* from tmp t where val = (select min(val) from tmp where name = t.name)
) m where px = (select min(px) from
(
select t.* from tmp t where val = (select min(val) from tmp where name = t.name)
) n where n.name = m.name)drop table tb,tmp/*
name val memo
---------- ----------- --------------------
a 1 a1--a的第一个值
b 1 b1--b的第一个值(2 行受影响)
*/
--在sql server 2005中可以使用row_number函数,不需要使用临时表。
--创建表并插入数据:
create table tb(name varchar(10),val int,memo varchar(20))
insert into tb values('a', 2, 'a2(a的第二个值)')
insert into tb values('a', 1, 'a1--a的第一个值')
insert into tb values('a', 1, 'a1--a的第一个值')
insert into tb values('a', 3, 'a3:a的第三个值')
insert into tb values('a', 3, 'a3:a的第三个值')
insert into tb values('b', 1, 'b1--b的第一个值')
insert into tb values('b', 3, 'b3:b的第三个值')
insert into tb values('b', 2, 'b2b2b2b2')
insert into tb values('b', 4, 'b4b4')
insert into tb values('b', 5, 'b5b5b5b5b5')
goselect m.name,m.val,m.memo from
(
select * , px = row_number() over(order by name , val) from tb
) m where px = (select min(px) from
(
select * , px = row_number() over(order by name , val) from tb
) n where n.name = m.name)drop table tb/*
name val memo
---------- ----------- --------------------
a 1 a1--a的第一个值
b 1 b1--b的第一个值(2 行受影响)
*/select t1.* , t2.* , t3.* from
(select t.* from pic t where a.uploader = 'XXXXXX' and a.shenhe = 'true' and id = (select min(id) from pic where uploader = 'XXXXXX' and shenhe = 'true' and picName = t.picName)) t1,
(select t.* from picFile t where id = (select min(id) from picFile where parentId = t.parentId) t2,
(select t.* from down t where id = (select min(id) from down where picFile = t.picFile) t3
where t1.id = t2.parentId and t2.picFile = t3.picFile
"b.units_id, b.units_name, "+
"c.ware_id, c.ware_num, c.ware_type "+
"FROM rms_goods a , rms_units b,rms_ware_stock c " +
"where a.goods_unit = b.units_id and a.goods_id = c.ware_id and a.goods_id = '"
+ goods_id + "'";