使用实体框架的输出参数执行SQL存储过程 [英] Executing SQL Stored Procedure with Output Parameter from Entity Framework

问题描述

使用EF，我试图执行返回单个字符串值的存储过程，即SQL Agent作业的状态。

Using EF, I'm trying to execute a stored procedure that returns a single string value, i.e. the status of an SQL Agent Job.

存储过程是声明为

CREATE PROCEDURE [dbo].[up_GetJobStatus](@JobStatus NVARCHAR(30) OUTPUT)
AS

-- some code omitted for brevity

SELECT @JobStatus = (
SELECT  
    CASE job_state 
    WHEN 1 THEN 'Executing'
    WHEN 2 THEN 'Waiting for thread'
    WHEN 3 THEN 'Between retries'
    WHEN 4 THEN 'Idle'
    WHEN 5 THEN 'Suspended'
    WHEN 6 THEN '<unknown>'
    WHEN 7 THEN 'Performing completion actions'
END
FROM @xp_results results 
INNER JOIN msdb.dbo.sysjobs sj
ON results.job_id = sj.job_id
WHERE sj.job_id = @job_id)

RETURN

我已经验证存储过程是正确的，因为我可以在查询窗口中执行它，并返回rns

I have verified the stored procedure is working correct as I can execute it in query window and it returns

    @JobStatus
  ------------
  1|Idle

但是，当使用EF执行时，参数值为NULL

However when executing with EF, the param value is NULL

var param = new SqlParameter
{
    ParameterName = "@JobStatus",
    DbType = DbType.String,
    Size = 30,
    Direction = System.Data.ParameterDirection.Output
};

var result = this.etlContext.Database.SqlQuery<string>("EXEC dbo.up_GetJobStatus @JobStatus OUTPUT", param);

我还尝试了 ExecuteSqlCommand 方法但是这还没有起作用。

I've also tried the ExecuteSqlCommand method but that didn't work either.

任何想法？

推荐答案

1. 在数据库中创建存储过程

。

 CREATE PROCEDURE [dbo].myStoredProcName
    @inputParam1 varchar(150),
    @inputParam2 varchar(150),
    @myOutputParamBool bit output,
    @myOutputParamString varchar(100) output,
    @myOutputParamInt int output
AS
BEGIN
    -- sql here
END

1. 从数据库更新实体模型以包含存储过程
   < a href =https://i.stack.imgur.com/61Bf9.png =nofollow noreferrer>如下所示

从C＃代码调用存储过程

Call stored proc from C# code

System.Data.Entity.Core.Objects.ObjectParameter myOutputParamBool=new System.Data.Entity.Core.Objects.ObjectParameter("myOutputParamBool",typeof(bool));

System.Data.Entity.Core.Objects.ObjectParameter myOutputParamString=new System.Data.Entity.Core.Objects.ObjectParameter("myOutputParamString",typeof(string));

System.Data.Entity.Core.Objects.ObjectParameter myOutputParamInt=new System.Data.Entity.Core.Objects.ObjectParameter("myOutputParamInt",typeof(Int32));

using (var context = new SandCryptEntities())
{
   context.myStoredProcName(inputParam1, inputParam2, myOutputParamBool, myOutputParamString, myOutputParamInt);   
}
            bool myBool = Convert.ToBoolean(myOutputParamBool.Value);
            string myString = Convert.ToString(myOutputParamString.Value);
            int myInt = Convert.ToInt32(myOutputParamInt.Value);

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