第十期代码linq查询操作符一

varquery fromein where select [Extent1].[EmployeeID]AS [Extent1].[LastName]AS [Extent1].[FirstName]AS [Extent1].[Title]AS [Extent1].[TitleOfCourtesy]AS [Extent1].[BirthDate]AS [Extent1].[HireDate]AS [Extent1].[Address]AS [Extent1].[City]AS [Extent1].[Region]AS [Extent1].[PostalCode]AS [Extent1].[Country]AS [Extent1].[HomePhone]AS [Extent1].[Extension]AS [Extent1].[Photo]AS [Extent1].[Notes]AS [Extent1].[ReportsTo]AS [Extent1].[PhotoPath]AS FROM[dbo].[Employees]AS WHERE[Extent1].[FirstName]LIKEvarq .Where(e=> .Select(e=> [Extent1].[EmployeeID]AS [Extent1].[LastName]AS [Extent1].[FirstName]AS [Extent1].[Title]AS [Extent1].[TitleOfCourtesy]AS [Extent1].[BirthDate]AS [Extent1].[HireDate]AS [Extent1].[Address]AS [Extent1].[City]AS [Extent1].[Region]AS [Extent1].[PostalCode]AS [Extent1].[Country]AS [Extent1].[HomePhone]AS [Extent1].[Extension]AS [Extent1].[Photo]AS [Extent1].[Notes]AS [Extent1].[ReportsTo]AS [Extent1].[PhotoPath]AS FROM[dbo].[Employees]AS WHERE[Extent1].[FirstName]LIKEvarqq .Where(e=> varquery fromein where select varquery1 db.Employees.Where(e=> .Select(e=> [Extent1].[FirstName]AS FROM[dbo].[Employees]AS WHERE[Extent1].[FirstName]LIKE如果想返回单列类， varquery1 db.Employees.Where(e=> .Select(e=>new{e.FirstName varquery (fromein where select varquery1 db.Employees.Where(e=> .Select(e=> 1AS [Extent1].[FirstName]AS [Extent1].[LastName]AS [Extent1].[Title]AS FROM[dbo].[Employees]AS WHERE[Extent1].[FirstName]LIKE查询多列，返回的是一个 varquery (fromein fromoin select varq .SelectMany(e=> [Extent1].[OrderID]AS[Extent1].[CustomerID]AS[Extent1].[EmployeeID]AS[Extent1].[OrderDate]AS[Extent1].[RequiredDate]AS[Extent1].[ShippedDate]AS[Extent1].[ShipVia]AS[Extent1].[Freight]AS[Extent1].[ShipName]AS[Extent1].[ShipAddress]AS[Extent1].[ShipCity]AS[Extent1].[ShipRegion]AS[Extent1].[ShipPostalCode]AS[Extent1].[ShipCountry]ASFROM[dbo].[Orders]ASWHERE[Extent1].[EmployeeID]ISNOT varquery (fromein orderby select varq .OrderBy(e=> [Extent1].[EmployeeID]AS[Extent1].[LastName]AS[Extent1].[FirstName]AS[Extent1].[Title]AS[Extent1].[TitleOfCourtesy]AS[Extent1].[BirthDate]AS[Extent1].[HireDate]AS[Extent1].[Address]AS[Extent1].[City]AS[Extent1].[Region]AS[Extent1].[PostalCode]AS[Extent1].[Country]AS[Extent1].[HomePhone]AS[Extent1].[Extension]AS[Extent1].[Photo]AS[Extent1].[Notes]AS[Extent1].[ReportsTo]AS[Extent1].[PhotoPath]ASFROM[dbo].[Employees]ASORDERBY[Extent1].[FirstName]因为未使用Select varquery (fromein orderbye.FirstName, select varq .OrderBy(e=> .ThenBy(e=> [Extent1].[EmployeeID]AS[Extent1].[LastName]AS[Extent1].[FirstName]AS[Extent1].[Title]AS[Extent1].[TitleOfCourtesy]AS[Extent1].[BirthDate]AS[Extent1].[HireDate]AS[Extent1].[Address]AS[Extent1].[City]AS[Extent1].[Region]AS[Extent1].[PostalCode]AS[Extent1].[Country]AS[Extent1].[HomePhone]AS[Extent1].[Extension]AS[Extent1].[Photo]AS[Extent1].[Notes]AS[Extent1].[ReportsTo]AS[Extent1].[PhotoPath]ASFROM[dbo].[Employees]ASORDERBY[Extent1].[FirstName]ASC,[Extent1].[LastName]varquery fromein orderbye.FirstName,e.LastName selectvarq .OrderBy(e=> .ThenByDescending(e=> .Select(e=>foreach(varitemin [Extent1].[EmployeeID]AS [Extent1].[LastName]AS [Extent1].[FirstName]AS [Extent1].[Title]AS [Extent1].[TitleOfCourtesy]AS [Extent1].[BirthDate]AS [Extent1].[HireDate]AS [Extent1].[Address]AS [Extent1].[City]AS [Extent1].[Region]AS [Extent1].[PostalCode]AS [Extent1].[Country]AS [Extent1].[HomePhone]AS [Extent1].[Extension]AS