Parsing string values in Access - sql

Question

I am importing sql into my Access database and am working on parsing the data into the correct tables and fields. Again I turn to you gurus to assist in a problem
One of the fields that is imported has comma separated values that need to be separated.there are anywhere from one to 10 possible values in the string.
PHO,Rosgen,NRCS,EMAP,T-DL,YSI-DL
I have figured out that if I make all of the values the same length (say 4 characters) I can get the 1st, last and 1st after the comma to parse but cannot seem to get the middle values extracted correctly.
SELECT Left([FieldForms],InStr([FieldForms],",")-1) AS DEQ_SampleTypeID
FROM tblSiteVisit
UNION ALL
SELECT Mid([FieldForms],InStr([FieldForms],",")+1,4) AS DEQ_SampleTypeID
FROM tblSiteVisit
UNION ALL
SELECT Mid([FieldForms], 11, 4) AS DEQ_SampleTypeID
FROM tblSiteVisit
UNION ALL
SELECT Mid([FieldForms], 16, 4) AS DEQ_SampleTypeID
FROM tblSiteVisit
UNION ALL
SELECT Mid([FieldForms], 21, 4) AS DEQ_SampleTypeID
FROM tblSiteVisit
UNION ALL
SELECT Mid([FieldForms],InStrRev([FieldForms],",")-4,4) AS DEQ_SampleTypeID
FROM tblSiteVisit
UNION ALL
SELECT Right([FieldForms],InStr([FieldForms],",")-1) AS DEQ_SampleTypeID
FROM tblSiteVisit
If I use the InStrRev or the Right Function I get repeats if there are fewer than the maximum also using the Mid functions results in empty rows.
Is there a way to parse out a string like this and only get results from the string

Answer 1

Put the following functions into a Module:
Function CountCSWords (ByVal S) As Integer
' Counts the words in a string that are separated by commas.
Dim WC As Integer, Pos As Integer
If VarType(S) <> 8 Or Len(S) = 0 Then
CountCSWords = 0
Exit Function
End If
WC = 1
Pos = InStr(S, ",")
Do While Pos > 0
WC = WC + 1
Pos = InStr(Pos + 1, S, ",")
Loop
CountCSWords = WC
End Function
Function GetCSWord (ByVal S, Indx As Integer)
' Returns the nth word in a specific field.
Dim WC As Integer, Count As Integer, SPos As Integer, EPos As Integer
WC = CountCSWords(S)
If Indx < 1 Or Indx > WC Then
GetCSWord = Null
Exit Function
End If
Count = 1
SPos = 1
For Count = 2 To Indx
SPos = InStr(SPos, S, ",") + 1
Next Count
EPos = InStr(SPos, S, ",") - 1
If EPos <= 0 Then EPos = Len(S)
GetCSWord = Trim(Mid(S, SPos, EPos - SPos + 1))
End Function
Then, put a field in your query like this:
MyFirstField: GetCSWord([FieldForms],1)
Put another one in like this:
MySecondField: GetCSWord([FieldForms],2)
Etc... for as many as you need.

Answer 2

This VBA code reads text values from FieldForms in tblSiteVisit, splits that text into substrings, and then stores each of the substrings in DEQ_SampleTypeID in a new row added to tblDestination.
Dim astrItems() As String
Dim db As DAO.database
Dim i As Long
Dim qdf As DAO.QueryDef
Dim rs As DAO.Recordset
Dim strInsert As String
strInsert = "INSERT INTO tblDestination (DEQ_SampleTypeID)" & vbCrLf & _
"VALUES ([array_item]);"
Set db = CurrentDb
Set rs = db.OpenRecordset("tblSiteVisit", dbOpenTable, dbOpenSnapshot)
Set qdf = db.CreateQueryDef(vbNullString, strInsert)
Do While Not rs.EOF
astrItems = Split(rs!FieldForms, ",")
For i = 0 To UBound(astrItems)
qdf.Parameters("array_item") = astrItems(i)
qdf.Execute dbFailOnError
Next
rs.MoveNext
Loop
rs.Close
Set rs = Nothing
Set qdf = Nothing
Set db = Nothing