0
ENV：EF6 +代碼首先調用自定義函數Where子句
我希望能夠調用自定義函數的LINQ查詢
的Where子句中所以這行：
var activeStaff = Repo.Staff.Where(s => s.EndDate == null || s.EndDate.Value > DateTime.Today);
變爲：
var activeStaff = Repo.Staff.Where(s => MyEdmFunctions.IsCurrentStaff(s));
這是我曾經嘗試過，
public class MyContext : DbContext
{
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Conventions.Add(new MyCustomConvention());
}
}
public class MyCustomConvention : IConceptualModelConvention<EdmModel>
{
public void Apply(EdmModel item, DbModel model)
{
var boolType = PrimitiveType.GetEdmPrimitiveType(PrimitiveTypeKind.Boolean);
var staffType = item.EntityTypes.Single(e => e.Name == "Staff");
var payLoad = new EdmFunctionPayload
{
ParameterTypeSemantics = ParameterTypeSemantics.AllowImplicitConversion,
IsComposable = true,
IsNiladic = false,
IsBuiltIn = false,
IsAggregate = false,
IsFromProviderManifest = true,
Parameters = new[] { FunctionParameter.Create("Staff", staffType, ParameterMode.In) },
ReturnParameters = new[] { FunctionParameter.Create("ReturnType", boolType, ParameterMode.ReturnValue) }
};
var function = EdmFunction.Create("IsCurrentStaff", "My.Core.Data", DataSpace.CSpace, payLoad, null);
item.AddItem(function);
}
}
public static class MyEdmFunctions
{
[DbFunction("My.Core.Data", "IsCurrentStaff")]
public static bool IsCurrentStaff(Staff s)
{
return s.EndDate == null || s.EndDate > DateTime.Today;
}
}
但是我得到了「不支持指定的方法」。錯誤從的EntityFramework的內部CTreeGenerator類（編譯後）
public override DbExpression Visit(NewRecordOp op, Node n)
{
throw new NotSupportedException();
}
可有人請確認是否真的沒有方法來調用在where子句中的自定義函數？
我知道可以創建一個存儲過程並將其映射到模型中。但有沒有辦法用C＃編寫它？
謝謝。