将txt文件插入数据库

Question

public partial class Form1 : Form
{

    public SqlConnection con = new SqlConnection(@"Data Source=(LocalDB)\v11.0;AttachDbFilename=C:\Users\Alexander\Desktop\Archivos.mdf;Integrated Security=True;Connect Timeout=30");



    private void Readbtn_Click(object sender, EventArgs e)
    {
         con.Open();
         Propiedades prop = new Propiedades();
         List<string> myValues = new List<string>();

         string line;

       StreamReader file = new StreamReader(@"c:\temp\archivo.txt");
        if ((line = file.ReadLine()) != null)
        {
            string[] fields = line.Split(',');
            prop.matricula = fields[0].ToString();
            prop.nombre = fields[1].ToString();
            prop.sueldo = decimal.Parse(fields[2]); 

            for (int i = 0; i < fields.Length; i++)
            {
                listBox1.Items.Add(fields[i]);
            }

        }



     SqlCommand cmd = new SqlCommand("INSERT INTO Archivos(Codigo, Nombre, Sueldo) VALUES (@Matricula, @Nombre, @Sueldo", con);
     cmd.Parameters.AddWithValue("@Matricula", prop.matricula);
     cmd.Parameters.AddWithValue("@Nombre", prop.nombre);
     cmd.Parameters.AddWithValue("@Sueldo", prop.sueldo);
     cmd.ExecuteNonQuery();

     con.Close();


 }

Hello Guys, I just need a little bit of help on modifying this code. I already have this to save the first line of the text file but I dont have any ideas on how to make it read the other lines. Also I would like to validate that if the SQL table contains already that info, it will launch an exception or message box letting the user know that the file already exist. Please help

Answer 1

I would recomend reading the file line by line, adding the values to a DataTable and then using SQL Bulk Insert to store it to the database.

It would be something like

int batchSize = 10000;

SqlBulkCopy bc = new SqlBulkCopy(con);

DataTable dtArchivos = new DataTable();
dtArchivos.Columns.AddRange(new []
{
    new DataColumn("Codigo", typeof(string)), 
    new DataColumn("Nombre", typeof(string)), 
    new DataColumn("Sueldo", typeof(decimal)), 
});
StreamReader file = new StreamReader(@"c:\temp\archivo.txt");
string line = file.ReadLine();
while (line != null)
{
    string[] fields = line.Split(',');
    DataRow dr = dtArchivos.NewRow();
    dr["Codigo"] = fields[0].ToString();
    dr["Nombre"] = fields[1].ToString();
    dr["Sueldo"] = decimal.Parse(fields[2]);
    dtArchivos.Rows.Add(dr);

    if (dtArchivos.Rows.Count == batchSize)
    {
        bc.WriteToServer(dtArchivos);
        dtArchivos.Clear();
    }
    line = file.ReadLine();
}
bc.WriteToServer(dtArchivos);

I added some logic to do batching, as a large file might cause the application to run out of memory due to the size of the DataTable.

Answer 2

There are a few things you need to do the the first that jumps out at me is that you want to use a while loop in place of your first if statement

    while ((line = file.ReadLine()) != null)
    {
        string[] fields = line.Split(',');
        prop.matricula = fields[0].ToString();
        prop.nombre = fields[1].ToString();
        prop.sueldo = decimal.Parse(fields[2]); 

        for (int i = 0; i < fields.Length; i++)
        {
            listBox1.Items.Add(fields[i]);
        }

    }

Also depending how you want to display the items in the list box you may want to use instead of that internal for loop:

listBox1.Items.Add(prop.matricula+','+prop.nombre+',prop.sueldo.toString());

Answer 3

First of all, consider using LINQ for your code - if you are not overly concerned about slightly more overhead, LINQ will make your life a whole lot easier. It will automatically cache the information for you, and can be more efficient for a lot of things, not to mention that the code is a lot easier to understand at times. For this, you would need to, in Visual Studio, create a ado.net model of the database, which shouldn't take too long. The precise way, I think, would be to

File -> Add Item -> Add new Item

or something of the like, then searching for ado.net entity. Then, just fill in the details that it asks. You can then use this entity (if you can't find out how to do it, then please reply so that I can fix it as need be) to add data, using the way that you specified.

Now, the reason why it may not be working code be a code problem. I think using the seperator may be the problem, and the following ammended code may be helpful:

StreamReader file = new StreamReader(@"c:\temp\archivo.txt");

    while(file.Read()){

    //YOUR CODE FOR CONCATENATING DATA HERE
}

The reason is that the reader would read until it has a return value of False or Null. Your code for some reason seems to be leaving after the first line, and this may solve it.