直接从控制器运行 SQL Server 存储过程

Question

我在 SQL Server 中有这个存储过程：

CREATE PROCEDURE current_call
    @call_id int
AS
BEGIN
    SET NOCOUNT ON;

    SELECT 
        dbo.Call.call_id, dbo.Call.city, dbo.Call.call_received, 
        dbo.Call.call_transfer, dbo.Call.call_response, dbo.Call.call_depart, 
        dbo.Call.call_arrive, dbo.Call.call_return, dbo.Call.call_end, 
        dbo.Priority.name AS priorityName, dbo.Call_Status.name as Call_Status, 
        dbo.Station.station_name, dbo.City.city_name, dbo.Protocol.name AS protocolName
    FROM     
        dbo.City 
    INNER JOIN
        dbo.Call 
    INNER JOIN 
        dbo.Priority ON dbo.Call.priority = dbo.Priority.priority_id 
        ON dbo.City.city_id = dbo.Call.city 
    INNER JOIN
        dbo.Protocol ON dbo.Call.protocol_category = dbo.Protocol.id 
    LEFT OUTER JOIN
        dbo.Station 
    INNER JOIN
        dbo.Ambulance ON dbo.Station.station_id = dbo.Ambulance.ambulance_station 
        ON dbo.Call.amb_id = dbo.Ambulance.ambulance_id
    INNER JOIN
        dbo.Call_Status ON dbo.Call.call_status = dbo.Call_Status.call_status_id
    WHERE 
        dbo.Call.call_id = @call_id;
END

我试图通过控制器调用它并将检索到的字段打印为json 字符串，但没有运气！

这是我的控制器：

public System.Web.Http.Results.JsonResult<String> GetTwo(int c_id)
{
    using (EMSMVCEntities entities = new EMSMVCEntities())
    {
        entities.Configuration.ProxyCreationEnabled = false;

        var query = entities.Database.SqlQuery<ObjectResult>("exec [dbo].[current_call] @call_id", new SqlParameter("call_id", c_id)).ToList();

        return Json (query.ToString());
    }
}

但是，我收到以下错误：

System.InvalidOperationException: '结果类型'System.Data.Entity.Core.Objects.ObjectResult' 可能不是抽象的，必须包含默认构造函数。'

我也试过下面的代码，结果是"-1"

var query = entities.Database.ExecuteSqlCommand("exec [dbo].[current_call] @call_id", new SqlParameter("call_id", c_id)).toString();

Answer 1

SqlQuery 不适用于动态类型：

如果你想使用动态类型或匿名类型作为它的 [SqlQuery] 返回类型，您可能会编译您的代码但收到 运行时异常。

另外请注意，您不能只调用ToString() 将您的List<object> 转换为json，您需要serialize 他们。

注意：在这个答案中，我将使用Newtonsoft.Json 进行序列化，但是还有其他options。

---

我建议为您的 SP 结果创建一个模型，这样您就可以将SqlQuery 的结果投影到您的模型中...定义模型还具有使用[JsonProperty] 属性的好处，这有助于映射您的将属性序列化为 json 时使用不同的名称。

public class CurrentCall
{
    // [JsonProperty(PropertyName = "Caller_Id")] <-- json property name (if different)
    public long call_id { get; set }
    public string city { get; set }
    public DateTime call_received { get; set }
    public string call_transfer { get; set }
    public string call_response { get; set }
    public DateTime call_depart { get; set }
    public DateTime call_arrive { get; set }
    public DateTime call_return { get; set }
    public DateTime call_end { get; set }
    public string priorityName { get; set }
    public bool Call_Status { get; set }
    public string station_name { get; set }
    public string city_name { get; set }
    public string protocolName { get; set }
}

那么就可以得到结果了：

var currentCalls = entities.Database.SqlQuery<CurrentCall>("exec [dbo].[current_call] @call_id", new SqlParameter("call_id", c_id)).ToList();

如果你想将结果返回为序列化的json，那么试试：

var jsonResult = JsonConvert.SerializeObject(currentCalls); 
return Json(jsonResult)