Question

Hi I have a text file with table schema and data when user checks not schema required then i need to delete schema and leave the data . I am using StreamReader to read the file and checking one condition and it should delete all the lines in the file till it satisfies my condition .
Let say if i am checking

  using (StreamReader tsr = new StreamReader(targetFilePath))
        {
            do
            {
                string textLine = tsr.ReadLine() + "\r\n";

                {
                    if (textLine.StartsWith("INSERT INTO"))
                    {

                         // It should leave these lines 
                        // and no need to delete lines 
                    }

                    else
                    {
                      // it should delete the lines 
                    }

                }
            }
            while (tsr.Peek() != -1);
            tsr.Close();  

Please suggest me how to delete lines and note if textline finds “InsertInto” it should not delete any content from there .

Answer 1

You read in the file just the same way you were doing. However, if the line doesn’t contain what you are looking for, you simply skip it. In the end, whatever data you are left over with you then write to a new text file.

            private void button1_Click(object sender, EventArgs e)
    {
        StringBuilder newText = new StringBuilder();
        using (StreamReader tsr = new StreamReader(targetFilePath))
        {
            do
            {
                string textLine = tsr.ReadLine() + "\r\n";

                {
                    if (textLine.StartsWith("INSERT INTO"))
                    {

                        newText.Append(textLine + Environment.NewLine);
                    }

                }
            }
            while (tsr.Peek() != -1);
            tsr.Close();
        }

        System.IO.TextWriter w = new System.IO.StreamWriter(@"C:\newFile.txt");
        w.Write(newText.ToString());
        w.Flush();
        w.Close();
    }