读取文本文件，然后将行分为几列

Question

I have an assignment where I need to read a text file and then breakdown each line into columns then I need to insert that into database.

What's the best approach for this? Any help will be appreciate it and if you could provide code will be even better.

This is what I have so far

    string filename = Server.MapPath("~/Text_File_4.txt");

    StreamReader sr = new StreamReader(filename);

    string styl;
    string colr;
    string sdim;
    string size;
    string qty;
    string line;

    string sprice;
    string sretail;

    while ((line = sr.ReadLine()) != null)

    {
        styl = line.Substring(0, 6);
        colr = line.Substring(6, 2);
        sdim = line.Substring(8, 1);
        size = line.Substring(14, 3);
        qty = line.Substring(19, 5);


        sprice = line.Substring(27, 6);
        sretail = line.Substring(38, 4);

        con.Open();
        cmd = new SqlCommand("insert into ststyl00(ststyl, stcolr, stsdim, stszcd, stprq, strprq) values(@ststyl, @stcolr, @stsdim, @stszcd, @stprq, @strprq)", con);

        cmd.Parameters.Add("@ststyl", SqlDbType.VarChar, 15).Value = styl;
        cmd.Parameters.Add("@stcolr", SqlDbType.VarChar, 3).Value = colr;
        cmd.Parameters.Add("@stsdim", SqlDbType.VarChar, 8).Value = sdim;
        cmd.Parameters.Add("@stszcd", SqlDbType.VarChar, 3).Value = size;

        cmd.Parameters.Add("@stprq", SqlDbType.VarChar, 8).Value = sprice;
        cmd.Parameters.Add("@strprq", SqlDbType.VarChar, 8).Value = sretail;
        cmd.ExecuteNonQuery();
        con.Close();



    }

Answer 1

Input is a CSV

If your input files are CSV files, I strongly recommend using the CSV Reader class available at

http://www.codeproject.com/Articles/9258/A-Fast-CSV-Reader

Input is Fixed-Width

If your input is fixed-width, just read all of the lines in and parse each individual line into an appropriate structure to store in the database (more on that in a moment).

If you have just a little text to read (perhaps a few megabytes or less), just use

File.ReadAllLines

http://msdn.microsoft.com/en-us/library/s2tte0y1

to read in all of the lines of the file into a string[] .

Writing to the DB

You now have a capability to read in the file. Now, you need to write it out to the database. Presumably there is a DB table with a given schema that matches the data in the file. Have a look at ADO.Net to understand how to write to a database and ask specific questions as needed.

http://msdn.microsoft.com/en-us/library/h43ks021(v=vs.100).aspx

Answer 2

This sounds like you have to have the text file with delimiter. The delimiter which separates the data into columns, eg

data1, data2, data3, data4

The delimiter could be comma or any other character which is not appearing into regular data. If you have the text file in this format, it would be easy to parse it and push it to database.

The approach could be - You open the file using StreamReader. Read the file line by line ie read a line at a time. Split the line into columns through specifying delimiter.

string[] lineData = sr.ReadLine().split('delimiter');
foreach(string colData in lineData)
{
     //store data into appropriate collections and push it to database
}

Answer 3

除了已经建议的其他解析技术之外，您还可以将TextFieldParser类（在Microsoft.VisualBasic.FileIO名称空间中）与已编写的ADO.Net代码一起使用。