我试图将SQL查询转换为vb中的linq查询。但我在使语法正确方面遇到了一些麻烦。
原始查询
SELECT b.*
FROM History_Table_B b
INNER JOIN Employee e ON b.EmployeeId = e.EmployeeId
INNER JOIN Company c ON e.CompanyId = c.CompanyId
WHERE e.AncillaryId = @AncillaryPersonId
AND c.AncillaryId = @AncillaryCompanyId
AND (b.EndDate is null OR b.EndDate >= convert(date, GetDate()))
My Linq
Dim result = From b In context.H_Table_B
Join employee In context.Employees
On b.EmployeeId Equals (employee.EmployeeId)
Join company In context.Companies
On employee.CompanyId Equals (company.CompanyId)
Where employee.AncillaryId Equals(iPerId)
And company.AncillaryId Equals (iCompanyId)
And ((b.EndDate Is Nothing) Or (b.EndDate Equals(DateTime.Today)))
答案 0 :(得分:6)
在何处条件下,您不能使用Equals(Operator),例如Join LINQ query。这里Equals是一个对象类的方法,因此您可以使用'。'进行访问。例如employee.AncillaryId.Equals(iCompanyId)
另外还有一件事,在新线VB.net的Where条件中需要'_'。
e.g。
From b In context.H_Table_B
Join employee In context.Employees
On b.EmployeeId Equals (employee.EmployeeId)
Join company In context.Companies
On employee.CompanyId Equals (company.CompanyId)
Where employee.AncillaryId.Equals(iPerId) _
And company.AncillaryId.Equals(iCompanyId) _
And ((b.EndDate Is Nothing) Or (b.EndDate.Equals(DateTime.Today)))
答案 1 :(得分:2)
我认为你只是错过了一个点 - 试试:
...b.EndDate.Equals(DateTime.Today)