Parsing CSV File enclosed with quotes in C#

Question

I\'ve seen lots of samples in parsing CSV File. but this one is kind of annoying file...

so how do you parse this kind of CSV

\"1\",1/2/2010,\"The sample (\"adas

Answer 1

There is one another open source library, Cinchoo ETL, handle quoted string fine. Here is sample code.

string csv = @"""1"",1/2/2010,""The sample(""adasdad"") asdada"",""I was pooping in the door ""Stinky"", so I'll be damn"",""AK""";

using (var r = ChoCSVReader.LoadText(csv)
    .QuoteAllFields()
    )
{
    foreach (var rec in r)
        Console.WriteLine(rec.Dump());
}

Output:

[Count: 5]
Key: Column1 [Type: Int64]
Value: 1
Key: Column2 [Type: DateTime]
Value: 1/2/2010 12:00:00 AM
Key: Column3 [Type: String]
Value: The sample(adasdad) asdada
Key: Column4 [Type: String]
Value: I was pooping in the door Stinky, so I'll be damn
Key: Column5 [Type: String]
Value: AK

Answer 2

You could split the string by ",". It is recomended that the csv file could each cell value should be enclosed in quotes like "1","2","3".....

Answer 3

As no (decent) .csv parser can parse non-csv-data correctly, the task isn't to parse the data, but to fix the file(s) (and then to parse the correct data).

To fix the data you need a list of bad rows (to be sent to the person responsible for the garbage for manual editing). To get such a list, you can

1. use Access with a correct import specification to import the file. You'll get a list of import failures.

2. write a script/program that opens the file via the OLEDB text driver.

Sample file:

"Id","Remark","DateDue"
1,"This is good",20110413
2,"This is ""good""",20110414
3,"This is ""good"","bad",and "ugly",,20110415
4,"This is ""good""" again,20110415

Sample SQL/Result:

 SELECT * FROM [badcsv01.csv]
 Id Remark               DateDue   
  1 This is good         4/13/2011 
  2 This is "good"       4/14/2011 
  3 This is "good",        NULL    
  4 This is "good" again 4/15/2011 

SELECT * FROM [badcsv01.csv] WHERE DateDue Is Null
 Id Remark          DateDue 
  3 This is "good",  NULL   

Answer 4

Split based on

",

I would use MyString.IndexOf("\","

And then substring the parts. Other then that im sure someone written a csv parser out there that can handle this :)

Answer 5

I very strongly recommend using TextFieldParser. Hand-coded parsers that use String.Split or regular expressions almost invariably mishandle things like quoted fields that have embedded quotes or embedded separators.

I would be surprised, though, if it handled your particular example. As others have said, that line is, at best, ambiguous.

Answer 6

First you will do it for the columns names:

            DataTable pbResults = new DataTable();
            OracleDataAdapter oda = new OracleDataAdapter(cmd);
            oda.Fill(pbResults);

            StringBuilder sb1 = new StringBuilder();
            StringBuilder sb2 = new StringBuilder();
            IEnumerable<string> columnNames = pbResults.Columns.Cast<DataColumn>().Select(column => column.ColumnName);

            sb1.Append(string.Join("\"" + "," + "\"", columnNames));                
            sb2.Append("\"");
            sb2.Append(sb1);
            sb2.AppendLine("\"");

Second you will do it for each row:

            foreach (DataRow row in pbResults.Rows)
            {
                IEnumerable<string> fields = row.ItemArray.Select(field => field.ToString());
                sb2.Append("\"");
                sb2.Append(string.Join("\"" + "," + "\"", fields));
                sb2.AppendLine("\"");
            }