Question

Table 1 

bln thn qty1    
1   2014    10  
1   2014    20  
2   2014    30  
3   2014    40  
2   2014    50  
4   2014    60  



Table 2

bln thn qty2    
3   2014    200 
5   2014    400 
2   2014    100 
2   2014    500 
4   2014    300 
6   2014    600 

New View

bln thn qty1    qty2
1   2014    30  0
2   2014    80  600
3   2014    40  200
4   2014    60  300
5   2014    0   400
6   2014    0   600

从顶部的2个表格开始，我想在底部创建一个类似于桌面的视图。

有人想帮忙吗？：D谢谢

Answer 1

--create a new view called newview
create view NewView as
--if table1 has a record for this bln use it; otherwise take table 2's value
select coalesce(t1.bln,t2.bln) bln
--same for thn
, coalesce(t1.thn,t2.thn) thn
--take the sum of qty1 calculated below (max used just because we need an aggregate - they're all the same
, max(t1.qty1) qty1
--same for qty2
, max(t2.qty2) qty2
--select from the tables summing the quantities here (so we have a 1:1 match on the join / don't have to sum for every match)
from (select bln, thn, sum(qty1) as qty1 from table1 group by bln, thn) t1
full outer join (select bln, thn, sum(qty2) as qty2  from table2 group by bln, thn) t2
    on t1.bln = t2.bln
    and t1.thn = t2.thn
--group by the common fields so we get 1 record per value combination
group by t1.bln, t2.bln, t1.thn, t2.thn

SQLFiddle：http://sqlfiddle.com/#!6/708da/1

Answer 2

我和@JohnBevan做了相同的选择，但有一些更改（不在主选上使用分组，也忘了命名内部选择列）

DECLARE @table1 TABLE (bln INT, thn INT, qty1 INT)

INSERT INTO @table1 SELECT 1,2014,10
INSERT INTO @table1 SELECT 1,2014,20
INSERT INTO @table1 SELECT 2,2014,30
INSERT INTO @table1 SELECT 3,2014,40
INSERT INTO @table1 SELECT 2,2014,50
INSERT INTO @table1 SELECT 4,2014,60

DECLARE @table2 TABLE (bln INT, thn INT, qty2 INT)

INSERT INTO @table2 SELECT 3,2014,200
INSERT INTO @table2 SELECT 5,2014,400
INSERT INTO @table2 SELECT 2,2014,100
INSERT INTO @table2 SELECT 2,2014,500
INSERT INTO @table2 SELECT 4,2014,300
INSERT INTO @table2 SELECT 6,2014,600

CREATE VIEW NewView AS
SELECT COALESCE(T1.bln, T2.bln) AS bln
    , COALESCE(T1.thn, T2.thn) AS thn
    , COALESCE(T1.qty1, 0) AS qty1
    , COALESCE(T2.qty2, 0) AS qty2
FROM (
    SELECT bln, thn, SUM(qty1) AS qty1
    FROM @table1
    GROUP BY bln, thn
) AS T1
FULL JOIN (
    SELECT bln, thn, SUM(qty2) AS qty2
    FROM @table2
    GROUP BY bln, thn
) AS T2
    ON T1.bln = T2.bln
    AND T1.thn = T2.thn

SQLFiddle：http://sqlfiddle.com/#!6/a3e2b/1

如何从这两个表创建一个视图？

2 个答案: