Question

In a For Each loop my VB program iterates over an collection.

Inside this loop I’m setting paramaters for the prepared statement.

Set param1 = cmd.CreateParameter("sync_id", adChar, adParamInput, Len(sync_id), sync_id)
Set param2 = cmd.CreateParameter("fieldname", adChar, adParamInput, Len(CName), CName)
Set param3 = cmd.CreateParameter("pvname", adChar, adParamInput, Len(pvname), pvname)
Set param4 = cmd.CreateParameter("value", adChar, adParamInput, Len(CNameVal), CNameVal)

And then appending them the Command Object.

cmd.Parameters.Append param1
cmd.Parameters.Append param2
cmd.Parameters.Append param3
cmd.Parameters.Append param4

When CNameVal (param4) is empty VB gives me an error: The paramater object is not defined properly.

I tried to solve this by checking CNameVal before creating the parameter:

If CNameVal = Empty Then
    Set param4 = cmd.CreateParameter("value", adEmpty, adParamInput)
    'Set param4 = cmd.CreateParameter("value")
    'Set param4 = cmd.CreateParameter("value", adEmpty, adParamInput, Len(CNameVal), CNameVal)
Else
    Set param4 = cmd.CreateParameter("value", adChar, adParamInput, Len(CNameVal), CNameVal)
End If

Neither of those lines solve problem. Any help appreciated!!

Answer 1

Len(Empty) = 0, which leads to an error. String length cannot be 0.
Correct practice here is to provide actual fixed length set in the database, not the length of the current string. I also doubt you need adChar, you probably meant adVarChar.

Your If doesn’t work because CNameVal = Empty is never going to be True. The correct way of checking for Empty is IsEmpty(CNameVal).