c# - 如何从 C# 函数的存储过程返回多个输出参数

Question

我正在使用输出参数从我的数据库中获取值。

这是我的存储过程：

ALTER PROCEDURE [dbo].[sp_GetCustomerMainData] 
    -- Add the parameters for the stored procedure here
        @Reference nvarchar(100),
        @SubscriptionPIN nvarchar(100) OUTPUT,
        @SignupDate nvarchar(100) OUTPUT,
        @ProductCount int OUTPUT
AS
BEGIN
    -- SET NOCOUNT ON added to prevent extra result sets from
    -- interfering with SELECT statements.
    SET NOCOUNT ON;

    SET @SubscriptionPIN = 'N/A'
    SET @SignupDate = 'N/A'
    SET @ProductCount = 0

    -- Insert statements for procedure here
    IF EXISTS(SELECT [SubscriptionPIN] FROM [Norton].[dbo].[Customers] WHERE [Reference] = @Reference)
    BEGIN
        SELECT TOP 1 @SubscriptionPIN = [SubscriptionPIN], @SignupDate = SignUpDate  FROM [Norton].[dbo].[ProductList] WHERE [Reference] = @Reference
        SET @ProductCount = (SELECT COUNT(*) FROM [Norton].[dbo].[ProductList] WHERE [Reference] = @Reference)
    END

    RETURN (@SubscriptionPIN)
    RETURN (@SignupDate)
    RETURN (@ProductCount)
END

我不确定最后的回报：

RETURN (@SubscriptionPIN)
RETURN (@SignupDate)
RETURN (@ProductCount)

另一方面，这里是 c# 代码：

using (SqlConnection con = new SqlConnection(connectionInfo))
{
    using (SqlCommand cmd = new SqlCommand("sp_GetCustomerMainData", con) { CommandType = CommandType.StoredProcedure })
    {
        cmd.Parameters.Add("@Reference", SqlDbType.NVarChar).Value = CustomerReferenceID;

        SqlParameter SubscriptionPIN = new SqlParameter("@TheCustomerID", SqlDbType.NVarChar) { Direction = ParameterDirection.Output };
        cmd.Parameters.Add(SubscriptionPIN);

        SqlParameter SignupDate = new SqlParameter("@SignupDate", SqlDbType.NVarChar) { Direction = ParameterDirection.Output };
        cmd.Parameters.Add(SignupDate);

        SqlParameter ProductCount = new SqlParameter("@ProductCount", SqlDbType.Int) { Direction = ParameterDirection.Output };
        cmd.Parameters.Add(ProductCount);

        con.Open();

        try
        {
            cmd.ExecuteNonQuery();

            if (cmd.Parameters["@TheCustomerID"].Value.ToString() != "N/A")
            {
                aStatus.SubscriptionPIN = cmd.Parameters["@TheCustomerID"].Value.ToString();
                aStatus.SignupDate = cmd.Parameters["@SignupDate"].Value.ToString();
                aStatus.ProductCount = int.Parse(cmd.Parameters["@ProductCount"].Value.ToString());
                aStatus.Result = "0: Reference ID Found";
             }
             else
             {
                 aStatus.Result = "1: Reference ID does not exists";
                 return aStatus;
             }
          }
          catch (SqlException sqlExc)
          {
              foreach (SqlError error in sqlExc.Errors)
              {
                  aStatus.Result = string.Format("{0}: {1}", error.Number, error.Message);
                  return aStatus;
              }
          }
      }
}

当我运行此代码时，出现错误：

System.InvalidOperationException：字符串 [1]：Size 属性在 System.Data.SqlClient.SqlParameter.Validate(Int32 index, Boolean isCommandProc)处的大小属性为0.Data.SqlClient.SqlCommand.SetUpRPCParameters
(_SqlRPC rpc, Int32 startCount, Boolean inSchema, SqlParameterCollection parameters)
at System.Data.SqlClient.SqlCommand.BuildRPC(Boolean inSchema, SqlParameterCollection parameters, _SqlRPC& rpc)
at System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async)
在 System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String 方法, DbAsyncResult 结果)
在 System.Data.SqlClient.SqlCommand.InternalExecuteNonQuery(DbAsyncResult 结果，字符串方法名，布尔 sendToPipe)
在 System.Data.SqlClient.SqlCommand.ExecuteNonQuery()

我不知道从存储过程发送许多输出参数的正确方法是什么，有人可以帮忙吗？

score 4 · Accepted Answer

您需要指定nvarchar参数的最大长度：

SqlParameter SubscriptionPIN = new SqlParameter("@TheCustomerID", SqlDbType.NVarChar, 100) { Direction = ParameterDirection.Output };
cmd.Parameters.Add(SubscriptionPIN);
SqlParameter SignupDate = new SqlParameter("@SignupDate", SqlDbType.NVarChar, 100) { Direction = ParameterDirection.Output };
cmd.Parameters.Add(SignupDate);

从存储过程中删除return语句。您无需为返回的输出参数执行任何操作。（此外，您只能使用一个return语句，并且只能返回整数值。您可以使用带方向的参数ReturnValue来获取该返回值。）

score 2 · Accepted Answer

过程执行在您的第一个 RETURN 之后结束，它“无条件地从查询或过程中退出”。

考虑将两个值作为一个记录集返回

SELECT @SubscriptionPIN AS SubsPIN , @SignupDate AS SignUpDate, @ProductCount AS ProdCount

在程序结束时。

score 1 · Accepted Answer

这是我尝试过的，它工作正常

**Stored Procedures**

STORED PROCEDURE 1

create procedure spLoginCount
@userid nvarchar(50),
@password nvarchar(50),
@count int out
as 
Begin 
    select @count=count(userid) from users where userid=@userid and pswd=@password
End



**STORED PROCEDURE 2**

create procedure spLoginData
@userid nvarchar(50),
@usertype nvarchar(20) out,
@lastlogin nvarchar(100) out
as 
Begin 
    select @usertype=usertype,@lastlogin=lastlogin from users where userid=@userid
End


**ASP.NET code which will get values of two output Parameters**....



 protected void btnLogin_Click(object sender, EventArgs e)
    {
        string uid="", psw="";
        uid = txtUserName.Text;
        psw = txtPassword.Text;

         string cs = ConfigurationManager.ConnectionStrings["DBCS"].ConnectionString;
         using (SqlConnection scon = new SqlConnection(cs))
         {
             SqlCommand scmd = new SqlCommand("spLoginCount", scon);
             scmd.CommandType = System.Data.CommandType.StoredProcedure;
             scmd.Parameters.AddWithValue("@userid",uid);
             scmd.Parameters.AddWithValue("@password", psw);

             SqlParameter outparameter = new SqlParameter();
             outparameter.ParameterName = "@count";
             outparameter.SqlDbType = System.Data.SqlDbType.Int;
             outparameter.Direction = System.Data.ParameterDirection.Output;
             scmd.Parameters.Add(outparameter);

             scon.Open();
             scmd.ExecuteScalar();

             string count = outparameter.Value.ToString();
             if (count == "1")
             {
                 SqlCommand scmd1= new SqlCommand("spLoginData", scon);
                 scmd1.CommandType = System.Data.CommandType.StoredProcedure;
                 scmd1.Parameters.AddWithValue("@userid", uid);

                 /*SqlParameter outUserType = new SqlParameter();
                 outUserType.ParameterName = "@usertype";
                 outUserType.SqlDbType = System.Data.SqlDbType.NText;
                 outUserType.Direction = System.Data.ParameterDirection.Output;
                 scmd1.Parameters.Add(outUserType);
                 */
                 SqlParameter outUserType = new SqlParameter("@usertype", SqlDbType.NVarChar, 100) { Direction = ParameterDirection.Output };
                 scmd1.Parameters.Add(outUserType);

                 SqlParameter outLastLogin = new SqlParameter("@lastlogin", SqlDbType.NVarChar, 100) { Direction = ParameterDirection.Output };
                 scmd1.Parameters.Add(outLastLogin);

                 scmd1.ExecuteNonQuery();
                 scon.Close();

                 string usertype,lastlogin;
                 usertype = outUserType.Value.ToString();
                 lastlogin = outLastLogin.Value.ToString();
               }

             }
         }

score 1 · Accepted Answer

>试试这个它对多输出参数的工作正常：

using (SqlConnection sqlConnection = new SqlConnection(ConfigurationManager.ConnectionStrings["conStringEndicia"].ConnectionString)){

                using (var sqlCmd = new SqlCommand("endicia.credentialLookup", sqlConnection))
                { 

                    sqlCmd.CommandType = System.Data.CommandType.StoredProcedure;
                    sqlCmd.Parameters.AddWithValue("@accountNumber", accountNumber);
                    SqlParameter outLogin = new SqlParameter("@login", SqlDbType.NVarChar, 100) { Direction = ParameterDirection.Output };
                    sqlCmd.Parameters.Add(outLogin);
                    SqlParameter outPassword = new SqlParameter("@password", SqlDbType.NVarChar, 100) { Direction = ParameterDirection.Output };
                    sqlCmd.Parameters.Add(outPassword);
                    sqlConnection.Open();
                    sqlCmd.ExecuteNonQuery();
                    string login, password;
                    login = outLogin.Value.ToString();
                    password = outPassword.Value.ToString();                        
                }
            }

score 0 · Accepted Answer

SqlParameter SubscriptionPIN = new SqlParameter("@TheCustomerID", SqlDbType.NVarChar, 100) { Direction = ParameterDirection.Output }; cmd.Parameters.Add(SubscriptionPIN); SqlParameter SignupDate = new SqlParameter("@SignupDate", DbType.String, 100 ) { Direction = ParameterDirection.Output }; cmd.Parameters.Add(SignupDate);

必须给出类型和尺寸

c# - 如何从 C# 函数的存储过程返回多个输出参数

5 回答 5

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