C# upload csv , column data type problem

See more:

C#

CSV

I use the code below to read data from a csv file. But the string values can't be read where the columns which are considered as a number column.
For example, there is a column which contains a string value "AAA", and the rest of this column contains number value such as 1,2,3. So when I read it, the string value will be read as "" instead of correct result "AAA".

please tell me how to deal with this problem, thanks.

//Fetch the location of CSV file 

string filePath = Server.MapPath("UploadedCSVFiles") + "\\";

string strSql = "SELECT * FROM [" + fileInfo.Name + "]";

string strCSVConnString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + filePath + ";" + "Extended Properties='text;HDR=YES;'";



// load the data from CSV to DataTable 



OleDbDataAdapter adapter = new OleDbDataAdapter(strSql, strCSVConnString);

DataTable dtCSV = new DataTable();

DataTable dtSchema = new DataTable();


adapter.FillSchema(dtCSV, SchemaType.Mapped);

adapter.Fill(dtCSV);

And I wonder if I can set the Jet to let all the columns are considered as string data type. And after select , I convert the string to number.