在关联子查询中使用WHERE时出错

Question

我有以下关系：银行 - ＆gt;融资 - ＆gt;合同 - ＆gt;供应商

我必须使用以下查询选择与供应商相关的所有银行：

SELECT DISTINCT A.Name AS BankName, A2.Name as SupplierName
FROM Companies A
INNER JOIN Financing F ON F.IdFinancialCompany = A.Id
INNER JOIN Contracts C ON F.IdContract = C.Id
INNER JOIN Companies A2 ON C.IdSupplier = A2.Id
GROUP BY A.Name, A2.Name

到目前为止，非常好。

现在我必须列出活动合同的数量和合同总数，所以我考虑包括一个子查询：

SELECT DISTINCT A.Name AS BankName, A2.Name as SupplierName,
(SELECT COUNT(C.Id)),
(SELECT COUNT(C.Id) WHERE C.ContractStatus = 1)
FROM Companies A
INNER JOIN Financing F ON F.IdFinancialCompany = A.Id
INNER JOIN Contracts C ON F.IdContract = C.Id
INNER JOIN Companies A2 ON C.IdSupplier = A2.Id 
GROUP BY A.Name, A2.Name

第2行运作良好，但我在第3行得到了na错误：

列＆＃39; Contracts.ContractStatus＆＃39;在选择列表中无效，因为它不包含在聚合函数或GROUP BY子句中。

我希望得到以下结果：

---

BANK NAME |供应商名称|总合同|有效合同

银行1 |供应商1 | 5 | 2

我怎样才能做到这一点？我正在使用SQL Server 2014

提前致谢！

Answer 1

从你的小组中删除不同的并使用CASE

SELECT A.Name AS BankName, A2.Name as SupplierName,
COUNT(C.Id),
SUM(CASE WHEN C.ContractStatus = 1 THEN 1 ELSE 0 END) 
FROM Companies A
INNER JOIN Financing F ON F.IdFinancialCompany = A.Id
INNER JOIN Contracts C ON F.IdContract = C.Id
INNER JOIN Companies A2 ON C.IdSupplier = A2.Id 
GROUP BY A.Name, A2.Name