MS Access Update Query (Multiple Where Conditions) - ms-access

Question

I have a textbox [ScanItem] on a Split Form that take two different barscan values, Works Really Slick!
Alphanumeric, Len 11
Numeric, Len 12
My Update Query works, but for only one WHERE Condition. I was hoping to use the Len function to combine the WHERE function's but can't get it to work.
Update Query for Alphanumeric Len 11 (Example: 019-WMD-001 ):
strSQL = "UPDATE [Location Table]" & _
"SET [Location]='" & Me.Location1.Value & "'" & _
"WHERE [Location Table].[Custom Label] = [ScanItem]"
Update Query for Numeric Len 12
"WHERE [Location Table].[Item ID] = [ScanItem]"
I understand the table spaces are a no-no but I do not have control over that. If this will not work, any other solution would be welcomed.

Answer 1

If I understand your question correctly you want to apply one WHERE clause evaluation if length of [ScanItem] = 11 (in which case use [Custom Label] in comparison) and another WHERE clause evaluation if length of [ScanItem] = 12 (in which case use [Item ID] in comparison). There are multiple ways to do this. I'm not addressing SQL injection issue--just the query logic, but you can always rewrite this using parameters (recommended best practice). You could write the query to use conditional logic or your vba could use the conditional logic (assuming there are only possible length conditions of 11 and 12). I'm a fan of scenario 2.
Scenario 1 (query uses conditional logic):
strSQL = "UPDATE [Location Table] " & _
"SET [Location]='" & Me.Location1.Value & "' " & _
"WHERE ([Location Table].[Custom Label] = '" & Me.ScanItem.Value & "' AND LEN('" & Me.ScanItem.Value & "') = 11) " & _
" OR ([Location Table].[Item ID] = '" & Me.ScanItem.Value & "' AND LEN('" & Me.ScanItem.Value & "') = 12)"
Scenario 2 (vba uses conditional logic--assuming only 2 possible lengths of 11 and not 11):
strSQL = "UPDATE [Location Table] " & _
"SET [Location]='" & Me.Location1.Value & "' " & _
"WHERE ([Location Table]." & IIF(Len(Me.ScanItem.Value)=11,"[Custom Label]","[Item ID]") & " = '" & Me.ScanItem.Value & "'"

Answer 2

For the first WHERE condition, you've handled it with string concatenation.
For the second one, however, you're just referring to the field.
A solution using string concatenation (at risk for SQL injection):
strSQL = "UPDATE [Location Table]" & _
" SET [Location]='" & Me.Location1.Value & "'" & _
" WHERE [Location Table].[Custom Label] = '" & Me.ScanItem.Value & "'"
A more proper solution using parameters:
strSQL = "UPDATE [Location Table]" & _
" SET [Location]= paramLocation" & _
" WHERE [Location Table].[Custom Label] = paramLabel"
Set qdf = CurrentDb.CreateQueryDef("", strSQL)
qdf.Parameters("paramLocation").Value = Me.Location1.Value
qdf.Parameters("paramLabel").Value = Me.ScanItem.Value
qdf.Execute