Question

我想将表连接到两个表，并希望得到以下格式的结果，

ID    Name1    Name2     StatusOfName2Yearwise   Year

我所尝试的是，

select t1.ID, t1.Name as 'Name1', t1a.Name as 'Name2', isnull(t2.Status,'N') as 'StatusOfName2Yearwise',Year
from
    table_1 t1, table_1 t1a
    LEFT JOIN table_3 t3 on t1a.id=t3.f_id
    LEFT JOIN table_2 t2  on t1a.ID=t2.id,
    table_4 t4 LEFT JOIN table_2 t2a on t4.Year=t2a.Fyr
where
     t1.ID=t3.f_id 
group by
    t1.ID, t1.Name, t1a.Name, t2.Status ,Year
order by
    t1.Name

这个查询给出了Name2的状态，但它不是逐年的，我想要它的年份。如果有人知道，请帮忙..

添加我从查询中获得的输出数据

 ID           Name1        Name2        StatusOfName2Yearwise     Year
 22           George       Julie              C                   2015           
 22           George       Julie              C                   2016       
 22           George       Julie              C                   2017

预期结果应如下所示，

 ID           Name1         Name2        StatusOfName2Yearwise    Year
 22           George        Julie             N                   2015           
 22           George        Julie             N                   2016       
 22           George        Julie             C                   2017

Answer 1

在不知道表格中的数据的情况下，我试图推断出其中的内容。

基于该测试数据，我构建了一个可以给出预期结果的SQL（Sql Server）。

桌面上的完整加入确保每年都会显示，即使表2中没有相应的Fyr。

对于测试，变量表的名称略有意义。

DECLARE @table_1_user TABLE (id int, Name varchar(8));
DECLARE @table_2_userstatus TABLE (id int, Status char(1), Fyr char(4));
DECLARE @table_3_userrelation TABLE (id int, f_id int);
DECLARE @table_4_year TABLE (Year char(4));

insert into @table_1_user values 
(22,'George'),
(23,'Julie');
insert into @table_2_userstatus values 
(22,'C','2016'),
(22,'X','2017'),
(23,'N','2016'),
(23,'C','2017');
insert into @table_3_userrelation values (22,23);
insert into @table_4_year values ('2015'),('2016'),('2017');

select distinct
t1a.id as Id1,
t1b.id as Id2,
t1a.Name as Name1,
t1b.Name as Name2,
isnull(t2b.Status,'N') as StatusOfName2Yearwise,
q.Year
from (
     select * from @table_3_userrelation t3
     full outer join @table_4_year t4 on (1=1)
) q
left join @table_1_user t1a on (q.id = t1a.id)
left join @table_1_user t1b on (q.f_id = t1b.id)
left join @table_2_userstatus t2b on (q.f_id = t2b.id and q.Year = t2b.Fyr)
order by t1a.Name, t1b.Name, q.Year;

这将得到以下结果：

Id1     Id2     Name1       Name2       StatusOfName2Yearwise       Year
22      23      George      Julie       N                           2015
22      23      George      Julie       N                           2016
22      23      George      Julie       C                           2017

如何将表连接到两个不同的表

1 个答案: