Question

Is it possible to BULK INSERT (SQL Server) a CSV file in which the fields are only OCCASSIONALLY surrounded by quotes? Specifically, quotes only surround those fields that contain a “,”.

In other words, I have data that looks like this (the first row contain headers):

id, company, rep, employees
729216,INGRAM MICRO INC.,"Stuart, Becky",523
729235,"GREAT PLAINS ENERGY, INC.","Nelson, Beena",114
721177,GEORGE WESTON BAKERIES INC,"Hogan, Meg",253

Because the quotes aren’t consistent, I can’t use ‘”,”‘ as a delimiter, and I don’t know how to create a format file that accounts for this.

I tried using ‘,’ as a delimter and loading it into a temporary table where every column is a varchar, then using some kludgy processing to strip out the quotes, but that doesn’t work either, because the fields that contain ‘,’ are split into multiple columns.

Unfortunately, I don’t have the ability to manipulate the CSV file beforehand.

Is this hopeless?

Many thanks in advance for any advice.

By the way, i saw this post SQL bulk import from csv, but in that case, EVERY field was consistently wrapped in quotes. So, in that case, he could use ‘,’ as a delimiter, then strip out the quotes afterwards.

Answer 1

You are going to need to preprocess the file, period.

If you really really need to do this, here is the code. I wrote this because I absolutely had no choice. It is utility code and I’m not proud of it, but it works. The approach is not to get SQL to understand quoted fields, but instead manipulate the file to use an entirely different delimiter.

EDIT: Here is the code in a github repo. It’s been improved and now comes with unit tests! https://github.com/chrisclark/Redelim-it

This function takes an input file and will replace all field-delimiting commas (NOT commas inside quoted-text fields, just the actual delimiting ones) with a new delimiter. You can then tell sql server to use the new field delimiter instead of a comma. In the version of the function here, the placeholder is <TMP> (I feel confident this will not appear in the original csv – if it does, brace for explosions).

Therefore after running this function you import in sql by doing something like:

BULK INSERT MyTable
FROM 'C:\FileCreatedFromThisFunction.csv'
WITH
(
FIELDTERMINATOR = '<*TMP*>',
ROWTERMINATOR = '\n'
)

And without further ado, the terrible, awful function that I apologize in advance for inflicting on you (edit – I’ve posted a working program that does this instead of just the function on my blog here):

Private Function CsvToOtherDelimiter(ByVal InputFile As String, ByVal OutputFile As String) As Integer

        Dim PH1 As String = "<*TMP*>"

        Dim objReader As StreamReader = Nothing
        Dim count As Integer = 0 'This will also serve as a primary key'
        Dim sb As New System.Text.StringBuilder

        Try
            objReader = New StreamReader(File.OpenRead(InputFile), System.Text.Encoding.Default)
        Catch ex As Exception
            UpdateStatus(ex.Message)
        End Try

        If objReader Is Nothing Then
            UpdateStatus("Invalid file: " & InputFile)
            count = -1
            Exit Function
        End If

        'grab the first line
    Dim line = reader.ReadLine()
    'and advance to the next line b/c the first line is column headings
    If hasHeaders Then
        line = Trim(reader.ReadLine)
    End If

    While Not String.IsNullOrEmpty(line) 'loop through each line

        count += 1

        'Replace commas with our custom-made delimiter
        line = line.Replace(",", ph1)

        'Find a quoted part of the line, which could legitimately contain commas.
        'In that case we will need to identify the quoted section and swap commas back in for our custom placeholder.
        Dim starti = line.IndexOf(ph1 & """", 0)
        If line.IndexOf("""",0) = 0 then starti=0

        While starti > -1 'loop through quoted fields

            Dim FieldTerminatorFound As Boolean = False

            'Find end quote token (originally  a ",)
            Dim endi As Integer = line.IndexOf("""" & ph1, starti)

            If endi < 0 Then
                FieldTerminatorFound = True
                If endi < 0 Then endi = line.Length - 1
            End If

            While Not FieldTerminatorFound

                'Find any more quotes that are part of that sequence, if any
                Dim backChar As String = """" 'thats one quote
                Dim quoteCount = 0
                While backChar = """"
                    quoteCount += 1
                    backChar = line.Chars(endi - quoteCount)
                End While

                If quoteCount Mod 2 = 1 Then 'odd number of quotes. real field terminator
                    FieldTerminatorFound = True
                Else 'keep looking
                    endi = line.IndexOf("""" & ph1, endi + 1)
                End If
            End While

            'Grab the quoted field from the line, now that we have the start and ending indices
            Dim source = line.Substring(starti + ph1.Length, endi - starti - ph1.Length + 1)

            'And swap the commas back in
            line = line.Replace(source, source.Replace(ph1, ","))

            'Find the next quoted field
            '                If endi >= line.Length - 1 Then endi = line.Length 'During the swap, the length of line shrinks so an endi value at the end of the line will fail
            starti = line.IndexOf(ph1 & """", starti + ph1.Length)

        End While

            line = objReader.ReadLine

        End While

        objReader.Close()

        SaveTextToFile(sb.ToString, OutputFile)

        Return count

    End Function