How to read quoted field from CSV using VBScript - parsing

Question

In a sample.csv file, which has fixed number of columns, I have to extract a particular field value and store it in a variable using VBScript.
sample.csv
100,SN,100.SN,"100|SN| 435623| serkasg| 15.32|
100|SN| 435624| serkasg| 15.353|
100|SN| 437825| serkasg| 15.353|"," 0 2345"
101,SN,100.SN,"100|SN| 435623| serkasg| 15.32|
100|SN| 435624| serkasg| 15.353|
100|SN| 437825| serkasg| 15.353|"," 0 2346"
I want to parse the last two fields which are within double quotes and store them in two different array variables for each row.

Answer 1

You could try using an ADO connection
Option Explicit
dim ado: set ado = CreateObject("ADODB.Connection")
ado.ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=c:\txtFilesFolder\;Extended Properties=""text;HDR=No;FMT=Delimited"";"
ado.open
dim recordSet: set recordSet = ado.Execute("SELECT * FROM [samples.csv]")
dim field3, field4
do until recordSet.EOF
field3 = recordSet.Fields(3).Value
field4 = recordSet.Fields(4).Value
' use your fields here
recordSet.MoveNext
loop
recordSet.close
ado.close
You may have an issue if those fields are greater than 255 characters in length - if they are, they may return truncated. You also may have better luck with ODBC or ACE connection strings instead of the Jet one I've used here.

Answer 2

Since CSV's are comma-separated, you can use the Split() function to separate the fields into an array:
' Read a line from the CSV...
strLine = myCSV.ReadLine()
' Split by comma into an array...
a = Split(strLine, ",")
Since you have a static number of columns (5), the last field will always be a(4) and the second-to-last field will be a(3).

Answer 3

Your CSV data seems to contain 2 embedded hard returns (CR, LF) per line. Then the first line ReadLine returns is:
100,SN,100.SN,"100|SN| 435623| serkasg| 15.32|
The solution below unwraps these lines before extracting the required fields.
Option Explicit
Const ForReading = 1
Const ForAppending = 8
Const TristateUseDefault = 2 ' Opens the file using the system default.
Const TristateTrue = 1 ' Opens the file as Unicode.
Const TristateFalse = 0 ' Opens the file as ASCII.
Dim FSO, TextStream, Line, LineNo, Fields, Field4, Field5
ExtractFields "sample.csv"
Sub ExtractFields(FileName)
Set FSO = CreateObject("Scripting.FileSystemObject")
If FSO.FileExists(FileName) Then
Line = ""
LineNo = 0
Set TextStream = FSO.OpenTextFile(FileName, ForReading, False, TristateFalse)
Do While Not TextStream.AtEndOfStream
Line = Line & TextStream.ReadLine()
LineNo = LineNo + 1
If LineNo mod 3 = 0 Then
Fields = Split(Line, ",")
Field4 = Fields(3)
Field5 = Fields(4)
MsgBox "Line " & LineNo / 3 & ": " & vbNewLine & vbNewLine _
& "Field4: " & Field4 & vbNewLine & vbNewLine _
& "Field5: " & Field5
Line = ""
End If
Loop
TextStream.Close()
Else
MsgBox "File " & FileName & " ... Not found"
End If
End Sub

Answer 4

Here is an alternative solution that allows for single or multiline CSV records. It uses a regular expression which simplifies the logic for handling multiline records. This solution does not remove CRLF characters embedded in a record; I've left that as an exercise for you :)
Option Explicit
Const ForReading = 1
Const ForAppending = 8
Const TristateUseDefault = 2 ' Opens the file using the system default.
Const TristateTrue = 1 ' Opens the file as Unicode.
Const TristateFalse = 0 ' Opens the file as ASCII.
Dim FSO, TextStream, Text, MyRegExp, MyMatches, MyMatch, Field4, Field5
ExtractFields "sample.csv"
Sub ExtractFields(FileName)
Set FSO = CreateObject("Scripting.FileSystemObject")
If FSO.FileExists(FileName) Then
Set MyRegExp = New RegExp
MyRegExp.Multiline = True
MyRegExp.Global = True
MyRegExp.Pattern = """([^""]+)"",""([^""]+)"""
Set TextStream = FSO.OpenTextFile(FileName, ForReading, False, TristateFalse)
Text = TextStream.ReadAll
Set MyMatches = MyRegExp.Execute(Text)
For Each MyMatch in MyMatches
Field4 = SubMatches(0)
Field5 = SubMatches(1)
MsgBox "Field4: " & vbNewLine & Field4 & vbNewLine & vbNewLine _
& "Field5: " & vbNewLine & Field5, 0, "Found Match"
Next
Set MyMatches = Nothing
TextStream.Close()
Else
MsgBox "File " & FileName & " ... Not found"
End If
End Sub