Very Computer

I have created a TQuery, SQLSumStockAmt, like this

Select Sum( Price * Qty) TotAmt
  From "stock.db" stock
Where PurId = :Pur_Id

Then in the Data Module, I assign the value to the parameter and open
the TQuery

  SQLSumStockAmt.Params[0].AsInteger := PurchasePurId.Value;
  SQLSumStockAmt.Open;

But when I  ShowMessage(IntToStr(Round(SQLSumStockAmtTotAmt.Value)));

The value is wrong!

What goes wrong?

Do you have the TQuery.DataSource property set to anything? Should not be,
unless this is the Detail table of a Master-Detail relationship.

Try using the same SQL statement, but viewing it in a visual data-aware
control. Is the result what you would expect?

Try expanding the SQL statement to include the PurID column in the SELECT
clause. (This also requires adding a GROUP BY, but just for this test
statement.) Is the value returned in the PurID column the expected one?

  SELECT SUM(Price * Qty) AS TotAmt
  FROM "stock.db"
  WHERE PurId = :Pur_Id

What is the result of using the value of the AsString property when
displaying the result set value with ShowMessage?

  ShowMessage(SQLSumStockAmtTotAmt.AsString);