使用实体框架创建查询5

问题描述

尝试转换为EF 5，但有 CreateQuery 有问题。任何帮助将不胜感激。谢谢你提前。

Trying to convert to EF 5 but having problems with CreateQuery. Any help would be much appreciated. Thank you in advance.

这是代码：

using System;
using System.ServiceModel;
using System.Data.Objects;
namespace TestingOneServiceRole
{
    public class Service1 : IService1
{
public void AddUser(string fullName, string userName, string password)
    {
        using (var context = new MyEntities())
        {
            context.AddToUser(new User()
            {
                UserName = userName,
                Password = password,
                FullName = fullName,
            });
            context.SaveChanges();
        }
    }
    public string UserLoginNow(string username, string password)
    {
        string query = @"SELECT value blah.FullName FROM MyEntities.blah AS User WHERE blah.UserName = @username AND blah.Password = @password";
        ObjectParameter[] parameters = new ObjectParameter[2];
        parameters[0] = new ObjectParameter("username", username);
        parameters[1] = new ObjectParameter("password", password);
        using (var context = MyEntities())
        {
            ObjectQuery<string> results = context.CreateQuery<string>(query, parameters);
            foreach (string result in results)
            {
 etc.......

推荐答案

我在此回应中假设您的MyEntities在EF5中继承自DbContext。

I assume in this response that your MyEntities inherits from DbContext in EF5.

使用SqlQuery的T）方法在DbContext.Database属性中完成同样的事情：

Use the SqlQuery(of T) method in the DbContext.Database property to accomplish the same thing:

public string UserLoginNow(string username, string password)
{
    string query = @"SELECT value blah.FullName FROM MyEntities.blah AS User WHERE blah.UserName = @username AND blah.Password = @password";
    object[] parameters = new object[2];
    parameters[0] = username;
    parameters[1] = password;
    using (var context = MyEntities())
    {
        IEnumerable<string> results = context.Database.SqlQuery<string>(query, parameters);
        foreach (string result in results)
        {
        }
    }
}

如果您的实体框架模型来自ObjectContext（而不是DbContext），那么请参阅这个链接如何访问EF5中的CreateQuery方法。

If your entity framework model dervies from ObjectContext (as opposed to DbContext) then see this link provided by @MarkSowul on how to get access to the CreateQuery method in EF 5.

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