Cannot perform = operation on string and Int32

[nkotbox]

I have developed this database frontend and am having this issue sometimes.
When I search for a serial # in my DB, sometimes I get the error "Cannot perform = operation on system.string and int32
What I cannot understand is this works for many serial #'s and does not work for others. Below is my code, is there a better way of doing this?

        Dim foundrows() As DataRow
        Dim thatserial = CInt(SerialTB.Text)
        Dim SerialSql As String = "[SerialNO] = " & (thatserial)
        'SerialSql = SerialSql & thatserial
        Dim SortDate As String = "dt"


        foundrows = dsCallLog.Tables("Call Log Sub").Select(SerialSql, SortDate)

I have tried taking out the cast to an integer but it did not work. I have wrapped the serial # in single quotes but then it never finds any records. Even records that currently work are not found when wrapped in single quotes. Is there a way to parameterize this so that it works better?

 

[Menthos]

The problem you're getting is down to how you build your SerialSql string...

Dim SerialSql As String = "[SerialNO] = " & (thatserial)

If your serial numbers are VARCHAR's in the DB, then I'm pretty sure you'll need to enclose the thatserial var in quotes to denote a string.

Dim SerialSql As String = "[SerialNO] = '" & thatserial.ToString() & "'"

 

[nkotbox]

In my post I stated that "I have wrapped the serial # in single quotes but then it never finds any records" . My try was a little different than yours but had the same output. I tried your suggestion just to be safe and had the same outcome. My first try looked like this:

Dim SerialSql As String = "[SerialNO] = " & "'" & (thatserial) & "'"

When I try this I get 0 results. I get 0 results for any serial # where currently the code works on most but no all serials. I do not see any difference in the DB to cause an issue. I went as far as to replace a line in the DB. I took a serial # that was working and replaced it with a serial # that does not work and it still didnt work. I thought that maybe some other field associated with the serial # was causing the issue.

In the DB, the SerialNO field is a text field.

If you have any other idea's Please let me know...

 

[Menthos]

My bad - should have spotted you'd tried the quotes.

Have you tried dropping a Try...Catch block around the offending code? If not, then it'd be a good point to stick a breakpoint at the Catch point and take a look at what's going on when the exception gets raised.

Do the textbox entered serial number's ever start with zero? Just a thought, given that casting to an integer will drop any leading zeroes.

 

[nkotbox]

All of the serial #'s start with 0. Oddly enough the serial #'s are found using the leading 0 or not. I had a breakpoint in the code where the error would happen and when I searched serial #'s that would work versus ones that would not work, I did not see any difference. Unexplainable to me.

However, When i deleted all calls associated with a non working serial #, that particular serial # can be called up and it works fine. I placed a few records against that serial # and no issues. It's as if there was some issue with the call records for that serial #. I looked at the data in the DB and did not see anything I thought was strange.

I have since fixed any serial # that was an issue and am moving on.

Thank you for the prompt replies as you helped me keep my sanity while working on this.

 

[Menthos]

Glad to hear you've got it working - no problem on the replies... keeps the grey matter ticking over