使用ExecuteScalar（）执行SP时如何在c＃中获取输出参数的值

Question

I am trying to execute a stored procedure in c#.

Stored procedure performs insert operation and returns values of one of the columns as output parameter.

I need to execute it from c# and get back value of output param.

Below is what i have tried so far.

SqlParameter[] associateParams = new SqlParameter[10];
            {
                 associateParams[0]=new SqlParameter("@orgName", newAssociate.OrgName);
                 associateParams[1]=new SqlParameter("@createdBy", newAssociate.Email);
                 associateParams[2]=new SqlParameter("@userName", newAssociate.UserName);
                 associateParams[3]=new SqlParameter("@workEmail", newAssociate.Email);
                 associateParams[4]=new SqlParameter("@password", newAssociate.Password);
                 associateParams[5]=new SqlParameter("@teamStrength", "0");
                 associateParams[6]=new SqlParameter("@projName", newAssociate.ProjName);
                 associateParams[7]=new SqlParameter("@userType", "Associate");
                 associateParams[8] = new SqlParameter("@userSalt", SqlDbType.VarChar, 400);
                 associateParams[8].Direction = ParameterDirection.Output;
                 associateParams[9] = new SqlParameter("@activationKey", SqlDbType.Int);
                 associateParams[9].Direction = ParameterDirection.Output;

            }

        using (SqlCommand cmd = con.CreateCommand())
        {
            log.Debug("In command is called");
            cmd.CommandType = CommandType.StoredProcedure;
            cmd.CommandText = ProcedureName;
            cmd.Parameters.AddRange(param);

            log.Debug("Command is called");
            try
            {
                if (con.State != ConnectionState.Open)
                {
                    con.Open();

                    log.Debug("Con is open");
                }
                cmd.ExecuteScalar();
                log.Debug(cmd.Parameters["@userSalt"].Value.ToString());
                log.Debug(cmd.Parameters["@activationKey"].Value.ToString());

Executing above, performs insert successfully but returns null for output params values.

Can anyone suggest what I am missing here.

Thanks

Answer 1

try like this when you define output parameters:

         associateParams[8] = new SqlParameter("@userSalt", SqlDbType.VarChar, 400);
         associateParams[8].Value = "";
         associateParams[8].Direction = ParameterDirection.Output;
         associateParams[9] = new SqlParameter("@activationKey", SqlDbType.Int);                 
         associateParams[9].Value = 0;
         associateParams[9].Direction = ParameterDirection.Output;

let me know if this helps.

UPDATE: here is my own method

 cmd.Parameters.Add(new SqlParameter("@userSalt", SqlDbType.VarChar, 400));
 cmd.Parameters["@userSalt"].Value = "";
 cmd.Parameters["@userSalt"].Direction = ParameterDirection.Output;

UPDATE1: because you dont use ExecuteNonQuery. Change cmd.ExecuteScalar() to cmd.ExecuteNonQuery()