Question

在将SUM(b.[Amount_withDiscount])和inner join on tables添加到之前正在运行的查询后，我收到了选择查询的错误消息。现在我希望查询也返回相关表中该列的总和。我哪里出错？

您尝试执行的查询不包含指定的表达式＆＃p; p。[PFirstName]＆amp; ＆＃39; ＆＃39; ＆安培; 。P [PLastName]＆＃39;作为集合函数的一部分。

工作查询

string sql = "SELECT p.[PFirstName]&' '&p.[PLastName] as [Patient Name],p.[Age],p.[BirthDate],p.[MobileNo]&' / '&p.[LandlineNo] as [Contact Number] FROM Patient_Registration p WHERE datepart('m',p.[RegDate])=@month AND datepart('yyyy',p.[RegDate])=@year AND p.DoctorID=" + drId;

添加sum和内部联接后的查询

string sql = "SELECT p.[PFirstName]&' '&p.[PLastName] as [Patient Name],p.[Age],p.[BirthDate],p.[MobileNo]&' / '&p.[LandlineNo] as [Contact Number], SUM(b.[Amount_withDiscount]) as [Payable Amount] FROM Patient_Registration p INNER JOIN Bill_Master b on p.[PatientID]=b.[Patient_ID] WHERE datepart('m',p.[RegDate])=@month AND datepart('yyyy',p.[RegDate])=@year AND p.DoctorID=" + drId;

Answer 1

当您添加SUM()表达式时，您将查询从常规选择查询更改为聚合查询，该查询期望每个输出字段为

聚合函数的一部分（SUM()，MAX()等）或
包含在GROUP BY子句中（查询中不存在）。

在这种情况下，对于一笔款项，您最好使用DSum()代替SUM()，例如

string sql = "SELECT p.[PFirstName]&' '&p.[PLastName] as [Patient Name],p.[Age],p.[BirthDate],p.[MobileNo]&' / '&p.[LandlineNo] as [Contact Number], DSum(\"Amount_withDiscount\",\"Bill_Master\",\"Patient_ID=\" & p.[PatientID]) as [Payable Amount] FROM Patient_Registration p WHERE datepart('m',p.[RegDate])=@month AND datepart('yyyy',p.[RegDate])=@year AND p.DoctorID=" + drId;

添加SUM（）表达式会导致我的Access查询停止工作

1 个答案: