VBA extract all fieldname within a string - excel

Question

I have a string like this one :
"'where CAST(a.DT_NPE_SORTIE as integer ) < cast (add_months (cast (a.dt_nep_restructuration as date format 'YYYYMMDD'), 12) as integer) and a.DT_NPE_SORTIE is not null and a.DT_NPE_SORTIE <> '99991231' and a.dt_npe_restructuration is not null and a.dt_npe_restructuration <> '99991231'"
I need to extract all "a.FIELDNAME" like a.dt_nep_restructuration, a.DT_NPE_SORTIE from the previous screen.
I need to do this in VBA for a project at work.
So far I used If & InStr to check if a list of value is present in the string. But it will be easier for me to extract all a.FIELDNAME then check if they match with fieldname in an array.
Best regards,
jouvzer

Answer 1

I saw there are many with "NPE" and one with "NEP"? Is that a typo? If it is, then will it always start with a.dt_nep_...? – Siddharth Rout 9 mins ago
No it's a typo in order to raise an error for my vba function. It will always start with "a." – Jouvzer 6 mins ago
I have handled both NPE/NEP. Is this what you are trying?
Option Explicit
Private Sub simpleRegex()
Dim strPattern As String: strPattern = "a.dt_(nep|npe)_\w+"
Dim regEx As Object
Dim strInput As String
Dim inputMatches As Object
Dim i As Long
strInput = "'where CAST(a.DT_NPE_SORTIE as integer ) < cast (add_months (cast (a.dt_nep_restructuration as date format 'YYYYMMDD'), 12) as integer) and a.DT_NPE_SORTIE is not null and a.DT_NPE_SORTIE <> '99991231' and a.dt_npe_restructuration is not null and a.dt_npe_restructuration <> '99991231'"
Set regEx = CreateObject("VBScript.RegExp")
With regEx
.Global = True
.MultiLine = True
.IgnoreCase = True
.Pattern = strPattern
End With
Set inputMatches = regEx.Execute(strInput)
If inputMatches.Count <> 0 Then
For i = 0 To inputMatches.Count - 1
Debug.Print inputMatches.Item(i)
Next i
End If
End Sub
Note: If it starts with a.dt then you can also use a.dt_\w+_\w+

Answer 2

Here is one RegExp based code which will print output for cell A1 in immediate window.
Public Sub FindMatches()
Dim oRgEx As Object, oMatches As Object
Dim i As Long
Set oRgEx = CreateObject("VBScript.RegExp")
With oRgEx
.Global = True
.MultiLine = True
.Pattern = "\ba\.[A-z_]+\b"
Set oMatches = .Execute(Range("A1").Value)
If oMatches.Count <> 0 Then
For i = 0 To oMatches.Count - 1
Debug.Print oMatches.Item(i)
Next i
End If
End With
End Sub
Depending on your actual data, you can adjust this further and adapt in your code.
Note: I am a basic level user of RegExp so you may want to consider suggestions indicated below such as \ba\.[A-Za-z_]+\b or \ba\.\w+\b if you get unusual results.

Answer 3

Simple alternative via Filter()
Filtering of all Split() elements in a string array containing the start identification a. allows to receive already a resulting array with all wanted elements (see section a) and b)).
An eventual cosmetic action removes unnecessary characters before the identifying prefix "a." (see section c))
Function ExtractFieldnames(s As String)
Const PREFIX As String = ".a"
'a) split string into tokens
Dim tmp() As String
tmp = Split(s, " ")
'b) leave only elements that include fieldnames
tmp = Filter(tmp, PREFIX, True)
'c) let them start with "a."
Dim i As Long
For i = 0 To UBound(tmp)
tmp(i) = PREFIX & Split(tmp(i), PREFIX)(1)
Next
'd) return array as function result
ExtractFieldnames = tmp
End Function
Example call
Sub TestExtract()
Dim s As String
s = "'where CAST(a.DT_NPE_SORTIE as integer ) < cast (add_months (cast (a.dt_nep_restructuration as date format 'YYYYMMDD'), 12) as integer) and a.DT_NPE_SORTIE is not null and a.DT_NPE_SORTIE <> '99991231' and a.dt_npe_restructuration is not null and a.dt_npe_restructuration <> '99991231'"
Debug.Print Join(ExtractFieldnames(s), vbNewLine)
End Sub
Results in VB Editor's immediate window
a.DT_NPE_SORTIE
a.dt_nep_restructuration
a.DT_NPE_SORTIE
a.DT_NPE_SORTIE
a.dt_npe_restructuration
a.dt_npe_restructuration