执行自定义查询-实体框架

ObjectQuery<DateTime> date = new ObjectQuery<DateTime>("select Getdate()", context)
DateTime now = date.Single();

你可以尝试这样的想法:

public static partial class ObjectContextExtension
{
    public static T ExecuteScalarCommand<T>(this ObjectContext context, string command)
    {
        DbConnection connection = ((EntityConnection)context.Connection).StoreConnection;
        if (connection.State == ConnectionState.Closed)
            connection.Open();

        DbCommand cmd = connection.CreateCommand();
        cmd.CommandText = command;
        cmd.CommandType = CommandType.Text;

        return (T)cmd.ExecuteScalar();
    }

它将方法“ExecuteEscalarCommand”添加到ObjectContext。
只需将SQL请求作为参数提供,并为泛型类型提供返回类型。

Public Function GetDateTimeFromServer() As DateTime
    Using context As New NorthwindEntities()
        Dim dateQry As IQueryable(Of DateTime) = From bogus In context.Products_
            Select DateTime.Now
        Dim result As DateTime = dateQry.First()
        Return result
    End Using
End Function

您可以对表(如products)使用查询,并确保您没有选择表中的任何列,如上面的代码所示。它不高雅,但很实用。