Question

I have a situation, where I am executing a stored procedure and fetching results in my c# code which returns 55 records, now I have a column in the row which needs to be displayed as a result of executing another sql query. I have tried all means, but couldn’t figure out how to achieve. Please help.

The C# code where I call the procedure which works fine is:

public static MonthlyFinancialReportCollection GetList(SASTransaction withinTransaction)
{
    MonthlyFinancialReportCollection records = null;

    using (DataSet ds = Helpers.GetDataSet("ShowPremiumCalcReport", withinTransaction))
    {
        if (ds.Tables.Count > 0)
        {
            records = new MonthlyFinancialReportCollection();

            foreach (DataRow dr in ds.Tables[0].Rows)
            {
                if (!string.IsNullOrEmpty(dr[0].ToString())) 
                     records.Add(FillDataRecord(dr));                        
            }
        }
    }

    return records;
}

Now I want to run a query, against the called procedure in the above function, so it will fill the one of the column with calculated result of the query.

select 
    Sum(WorkingHours.WHO_Amount * dbo.PremiumLevel.PLE_Premium) as Snr_Teaching_Amt
from policy, policyline, coveroption,
     premiumlevel, WorkingHours
where policy.pol_id=policyline.pli_pol_id 
and   policyline.pli_cop_seniorteachingcoverid=coveroption.cop_id 
and   premiumlevel.ple_own_id=policy.pol_own_id 
and   premiumlevel.ple_sca_id=coveroption.cop_sca_id 
and   WorkingHours.who_pos_id=policyline.pli_pos_id
and   pol_dcsf=row["snr teaching staff"]`

Answer 1

The slowest and easiest way:

• Make your second query a stored procedure which accepts “snr teaching staff”
  As a parameter.
• Add a new column to your DataTable from first query using:
  ds.Tables[0].Columns.Add(“Snr_Teaching_Amt”, typeof(decimal));
• Create a SqlCommand and a SqlParameter for the second stored procedure you created.
• Loop the DataTable and put “snr teaching staff” in value of SqlParameter.
• Run the SqlCommand using ExecuteScalar, the returned value is the result of your second query which you can keep in your created column.

However I don’t recommend this way because you’ll have 55 + 1 server round trips which is not cool.

The in-between way:

Since your second query returns a single value, make the second query a Sql function. You can call it in the first procedure like:

SELECT *, dbo.MyFunction([snr teaching staff]) AS Snr_Teaching_Amt FROM ...

This will have better performance and is easier to maintain.
However I agree with Massanu, you can combine the procedures using sub queries. Best of luck 😉