如何結合兩個case case列

我已經創建了2個case語句來從單個表中提取數據（它被創建爲2個單獨的case語句，因爲我想對double值進行計數，並且作爲單個case語句，它沒有做這個）。如何結合兩個case case列

這兩個case語句導致了2個新的數據列（case case A和case statement B）。不過，我希望將2個case語句值報告在一個列中，所以我試圖找到一種方法將這兩個列合併在一起。

這是我的查詢，因爲它代表。我對SQL很陌生（只過了一個星期！）所以請原諒我的查詢中的任何愚蠢的語法。

select b.part_month, count(a.pay_code), sum(a.amount), 
CASE 
when a.pay_code like 'CC%' THEN 'Credit Card Payment' 
when a.pay_code like 'DC%' then 'Debit Card Payment' 
Else 'N/A' 
End as Payment_Type, 

CASE 
when a.pay_code like '%IP%' then 'Internet Payment' 
when a.pay_code like '%TT%' then 'Touchtone Payment' 
Else 'N/A' 
End as Payment_Type 

from table_a A 
inner join table_b B on A.form_ID = B.ID 
where a.trans_type > 0 
and b.st_id = 2 

group by B.PART_MONTH, 
CASE 
when a.pay_code like 'CC%' THEN 'Credit Card Payment' 
when a.pay_code like 'DC%' then 'Debit Card Payment' 
Else 'N/A' 
End, 

CASE 
when a.pay_code like '%IP%' then 'Internet Payment' 
when a.pay_code like '%TT%' then 'Touchtone Payment' 
Else 'N/A' 
End 
order by b.part_month asc;

來源

2017-08-14 mrochester

你的情況下表達列都需要不同的別名。 – jarlh

好的，我可以做到這一點，但我該如何將它們結合在一起？ – mrochester

添加一些示例表格數據和預期結果 - 作爲格式化文本！ – jarlh

給你CASE聲明別名，然後包裝一下你的查詢GROUP BY別名。

還組合了您的CASE報表，假設這是您想要的。

SELECT * FROM (
    SELECT b.part_month, 
    COUNT(a.pay_code) AS PayCodeCount, 
    SUM(a.amount) AS AmountSum, 
    CASE a.pay_code 
     WHEN 'CC%' THEN 'Credit Card Payment' 
     WHEN 'DC%' THEN 'Debit Card Payment' 
     WHEN '%IP%' THEN 'Internet Payment' 
     WHEN '%TT%' THEN 'Touchtone Payment' 
     ELSE 'N/A' 
    END AS Payment_Type 
    FROM table_a A 
    INNER JOIN table_b B ON A.form_ID = B.ID 
    WHERE a.trans_type > 0 
    AND b.st_id = 2) Z 
GROUP BY PART_MONTH, Payment_Type 
ORDER BY part_month ASC;

來源

2017-08-14 10:35:31 Matt

我猜測你想要的：

select b.part_month, count(a.pay_code), sum(a.amount), 
     (case when a.pay_code like 'CC%' then 'Credit Card Payment' 
      when a.pay_code like 'DC%' then 'Debit Card Payment' 
      when a.pay_code like '%IP%' then 'Internet Payment' 
      when a.pay_code like '%TT%' then 'Touchtone Payment' 
      else 'N/A' 
     end) as Payment_Type 
from table_a a inner join 
    table_b b 
    on a.form_ID = b.ID 
where a.trans_type > 0 and b.st_id = 2 
group by b.part_month, 
     (case when a.pay_code like 'CC%' then 'Credit Card Payment' 
       when a.pay_code like 'DC%' then 'Debit Card Payment' 
       when a.pay_code like '%IP%' then 'Internet Payment' 
       when a.pay_code like '%TT%' then 'Touchtone Payment' 
       else 'N/A' 
      end) 
order by b.part_month asc;

重要：某些數據庫將允許您使用別名在group by，接受group by b.part_month, payment_type。

來源

2017-08-14 10:40:22

謝謝你的幫助。 Gordon Linoff，我已經嘗試過您的查詢，但是這會得到我在將案例陳述分解爲2之前最初開始的結果。

pay_code％IP％和％TT％也可以匹配CC％和DC％語句，並且當它這樣做時，它不計算IP或TT值。但是，即使這意味着對某些數據行進行雙重計數，我仍需要計算與IP％，％TT％，CC％和DC％匹配的所有值。

因此，pay_code列中的值可能是'DCIP'，'CCTT'，'CCIP'等。從這些值中，我想知道1個DC支付，2個CC支付，2個IP支付和1 TT付款。

這就是我的表最終如何看待單個案例的聲明。請注意，沒有Internet付款或付款條目。

Credit Card Payment 
Debit Card Payment 
N/A 
Credit Card Payment 
Debit Card Payment 
N/A 
Credit Card Payment 
Debit Card Payment 
N/A 
Credit Card Payment 
Debit Card Payment 
N/A 
Credit Card Payment 
Debit Card Payment 
N/A 
Credit Card Payment 
Debit Card Payment 
N/A 
Credit Card Payment 
Debit Card Payment 
N/A 
Credit Card Payment 
Debit Card Payment 
N/A 
Credit Card Payment 
Debit Card Payment 
N/A 
Credit Card Payment 
Debit Card Payment 
N/A 
Credit Card Payment 
Debit Card Payment 
N/A 
Credit Card Payment 
Debit Card Payment 
N/A 
Credit Card Payment 
Debit Card Payment 
N/A 
Credit Card Payment 
Debit Card Payment 
N/A 
Credit Card Payment 
Debit Card Payment 
N/A 
Credit Card Payment 
Debit Card Payment 
N/A 
Credit Card Payment 
Debit Card Payment

來源

2017-08-14 10:53:31 mrochester

答案是

Select * from (select b.part_month, count(a.pay_code), sum(a.amount), 
CASE 
when a.pay_code like '%IP%' then 'Internet Payment' 
when a.pay_code like '%TT%' then 'Touchtone Payment' 
Else 'N/A' 
End as Payment_Type 

from table_a A 
inner join table_b B on A.form_ID = B.ID 
where a.trans_type > 0 
and b.st_id = 2 

group by B.PART_MONTH, 
CASE 
when a.pay_code like '%IP%' then 'Internet Payment' 
when a.pay_code like '%TT%' then 'Touchtone Payment' 
Else 'N/A' 
End 

Union 

select b.part_month, count(a.pay_code), sum(a.amount), 
CASE 
when a.pay_code like 'CC%' THEN 'Credit Card Payment' 
when a.pay_code like 'DC%' then 'Debit Card Payment' 
Else 'N/A' 
End as Payment_Type 

from table_a A 
inner join table_b B on A.form_ID = B.ID 
where a.trans_type > 0 
and b.st_id = 2 

group by B.PART_MONTH, 
CASE 
when a.pay_code like 'CC%' THEN 'Credit Card Payment' 
when a.pay_code like 'DC%' then 'Debit Card Payment' 
Else 'N/A' 
End) 

Order by 1,4;

來源

2017-08-14 14:21:09 mrochester

如何結合兩個case case列

回答

相關問題