The Looping and Making Decisions Try It Out, Line 5, asks you Save the files and run.

If you get an error (Invalid cast exception ...) on code line:

GoalsFor += Convert.ToInt32(rdr("GoalsFor"))

it is because the database table Fixtures contains a record for the BuyChester United team with NULL values in the goalsfor and goals against fields. (A try-catch block could have caught this.)

To fix this: Use the Database explorer to navigate to the WroxUnited.mdf database tables, right click the Fixtures table and select Show Table Data. When the table displays, you can manually enter non-NULL values. The \End\Chapter09 shows values: GoalsFor = 1 and GoalsAgainst = 2 and you should replace the NULLs with those if you want to exactly duplicate the results shown in Figure 9-8.

VV

You could also use IIF to check if null, then return 0; otherwise return the integer value.

Brian

Brian:
Thanks.
Yes you are right. I thought correcting the missing data in the database would be a more appropriate fixup than adding code to proceed without throwing the exception.
But Thanks
VV

The data is Read Only. You need an Update command.

How To:
- After you open the database table Fixtures
- Change Type to Update
- Make changes to GoalsFor and Goals Against
- Move record pointer to another row. This writes the data.

or
- Change Type is Update
- past this code into the "Show Sql Pane"
UPDATE Fixtures
SET GoalsFor = 1, GoalsAgainst = 2
WHERE (FixtureID = 10)

and selct the Execute icon (exclamation)

Result will show 1 Row affected by last query