从文本文件加载数据并将其存储到数据库的最快方法

Question

I have problem.

I'm developing a project but I'm stuck in this part:

I want to load a data from text file and store it into database access the things is the data inside each text file about 12.000 lines of data and each text file it takes about 10 minute to process it..

NOTE : before store the data, I separate each line of data from text file and put it into string then I check whether the data is already inside database or not. if inside the database I update it. If not then I use insert statement..

I'm using C# to develop this program? is there any fastest way to load and store this data?

UPDATED:

This is my code I hope it will help to understand my problems:

    using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.IO;
using System.Collections;
using System.Data.OleDb;

namespace DAF
{
    public partial class FrontForm : Form
    {
        public Boolean status;

        public FrontForm()
        {
            InitializeComponent();

            //define location of the database
            string connection = @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\Users\PC\Desktop\Graduation Project\Research\DAF\Data\DAFLogisticDepartment.mdb";

            //define location of the text file data
            DirectoryInfo di = new DirectoryInfo(@"C:\Users\PC\Desktop\Graduation Project\Research\DAF\Data\");
            FileInfo[] fiarr = di.GetFiles("*.txt");


            //define connection to database
            OleDbConnection con = new OleDbConnection(connection);
            String query;
            OleDbDataReader rdr = null;

            con.Open();
            //get all table from database
            OleDbCommand cmd = con.CreateCommand();
            DataTable dt = con.GetSchema("tables");
            DataRow[] dttable = dt.Select();
            con.Close();

            //read each new textfile inside the folder
            foreach (FileInfo fri in fiarr)
            {
                StreamReader sr = new StreamReader(fri.FullName, System.Text.Encoding.Default);
                String line;
                String tabledbs, dbsName;

                while ((line = sr.ReadLine()) != null)
                {
                    String VRSD, locationID, truckID, yearIn, yearOut, weekIn, weekOut, dayIn, dayOut, timeIn, timeOut, route;
                    int plantID;

                    //process each line of data and put into each variable
                    VRSD = line.Substring(0, 4).Trim();
                    plantID = Convert.ToInt32(line.Substring(4, 1).Trim());
                    locationID = line.Substring(5, 4).Trim();
                    truckID = line.Substring(24, 5).Trim();
                    yearIn = line.Substring(32, 4).Trim();
                    weekIn = line.Substring(36, 2).Trim();
                    dayIn = line.Substring(38, 1).Trim();
                    timeIn = line.Substring(39, 8).Trim();
                    yearOut = line.Substring(47, 4).Trim();
                    weekOut = line.Substring(51, 2).Trim();
                    dayOut = line.Substring(53, 1).Trim();
                    timeOut = line.Substring(54, 8).Trim();
                    route = line.Substring(64, 2).Trim();

                    //make database name
                    dbsName = plantID + locationID;

                    con.Open();
                    //check if the table exist in database
                    for (int i = 0; i < dttable.Length - 9; i++)
                    {
                        tabledbs = dttable[i]["TABLE_NAME"].ToString();
                        ArrayList indexlist = new ArrayList();

                        if (tabledbs == dbsName)
                        {
                            //if the table exist, status = true
                            status = true;
                            break;
                        }
                    }
                    con.Close();

                    con.Open();

                    if (status == true)
                    {

                        try
                        {        
                            //if the data not in the system, insert statement
                            query = @"insert into " + plantID + locationID + " values('" + VRSD.ToString() + "'," + plantID + ",'" + locationID + "','" + truckID + "','" + yearIn + "','" + weekIn + "','" + dayIn + "','" + timeIn + "','" + yearOut + "','" + weekOut + "','" + dayOut + "','" + timeOut + "')";
                            cmd = new OleDbCommand(query, con);
                            rdr = cmd.ExecuteReader();
                            con.Close();
                        }
                        catch
                        {
                            //if the data in the system, update statement
                            query = @"update " + dbsName + " set YearIn='" + yearIn + "', YearOut='" + yearOut + "', WeekIn='" + weekIn + "', WeekOut='" + weekOut + "', DayIn='" + dayIn + "', DayOut='" + dayOut + "', TimeIn='" + timeIn + "', TimeOut='" + timeOut + "' where LocationID='" + locationID + "' and PlantID=" + plantID + "";
                            cmd = new OleDbCommand(query, con);
                            rdr = cmd.ExecuteReader();
                            con.Close();
                        }

                    }
                    else
                    {
                        //create new table
                        string attribute = "VRSD String,PlantID Integer, LocationID String, TruckID String," +
                                            "YearIn String, WeekIn String, DayIn String, TimeIn String," +
                                            "YearOut String, WeekOut String, DayOut String, TimeOut String";

                        query = @"CREATE TABLE " + plantID + locationID + "(" + attribute + ")";
                        cmd = new OleDbCommand(query, con);
                        cmd.ExecuteNonQuery();

                        //insert the data
                        query = @"insert into " + plantID + locationID + " values('" + VRSD.ToString() + "'," + plantID + ",'" + locationID + "','" + truckID + "','" + yearIn + "','" + weekIn + "','" + dayIn + "','" + timeIn + "','" + yearOut + "','" + weekOut + "','" + dayOut + "','" + timeOut + "')";
                        cmd = new OleDbCommand(query, con);
                        rdr = cmd.ExecuteReader();
                        con.Close();
                    }

                    status = false;
                }
                sr.Close();

                //after the text file load into database, the text file moved to history folder
                MessageBox.Show(fri.FullName.ToString(), "File Manager", MessageBoxButtons.OK);
                fri.MoveTo(@"C:\Users\PC\Desktop\Graduation Project\Research\DAF\Data\History\" + fri.Name.ToString() + ".txt");
            }
        }

        private void button2_Click(object sender, EventArgs e)
        {
            StandardReport sr = new StandardReport();
            sr.Show();
        }

        private void FrontForm_Load(object sender, EventArgs e)
        {

        }
    }
}

Answer 1

The big time killer here will be the sheer number of database connections you are using - try building an in-memory list of commands (which will take almost no time per object compared with reading the data from the file), and once you've built your list, execute them all over a single connection. It takes time to open each connection and you're doing that far more times than needed. Edit - actually noticed you are opening/closing 2 connections per line per file!

---

Currently (pseudo code for clarity):

For each file (x6)

   Load file from stream

   For each line in file (x12k)

     Read data from line

     Open database connection (happens 72k times)
     Check whether table exists
     Close connection

     Open connection (x72k)
     Try to insert record
     If inserting fails, update existing record
     Close connection

     Next line

   Close filestream

Next file

Suggestion: (and strongly suggest you think about the implications of adding tables dynamically, it's not normally a good solution, but if it's imposed on you maybe you have no choice)

Create an in-memory list of commands 
  (or list of custom objects with property for each command type, create 
  table,insert,update)    

For each file (x6)

   Load file from stream

   For each line in file (x12k)

      Read data from line (all happens 72k times, but no external connections per line)

      Write your create table command
      Write your insert command
      Write your update command
      Add to relevent command lists

   Next Line

   Close filestream

Next File

Open database connection (x1)

For each command in your list
   Apply suitable logic as to whether command needs to execute
   Execute command if applicable
Next command

Close database connection

Answer 2

Why don't you try creating and using an SSIS package? It's very good at this sort of thing, has excellent tooling and quite simple to use from code

http://msdn.microsoft.com/en-us/library/ms141026.aspx

http://blogs.msdn.com/b/michen/archive/2007/03/22/running-ssis-package-programmatically.aspx

Answer 3

You can use a query to insert unmatched records using the Jet driver for text.

SELECT a.* INTO NewTable FROM 
(SELECT * From [Text;DSN=Import Link Specification;FMT=Delimited;HDR=NO;IMEX=2;CharacterSet=850;DATABASE=C:\Docs].[Import.txt]) As A
LEFT JOIN OldTable ON a.Key=OldTable.Key
WHERE a.Key Is Null

EDIT

I wonder why you do not have a main table containing all plants and locations. You could then insert all the files into a temp table and either append or update from temp accordingly.

foreach (FileInfo fri in fiarr)
    {
    string s = "[Text;DSN=Test Spec;"
         + "FMT=Fixed;HDR=Yes;IMEX=2;CharacterSet=850;DATABASE=" 
         + fri.DirectoryName + "].["
         + fri.Name + "]";

    query = "INSERT INTO Temp SELECT * FROM " + s;

    cmd.ExecuteNonQuery();
    }

You seem to be using a fixed length format, so DSN=Test Spec is an Access specification create by exporting the file in fixed-width format and then saving the specification using the Advanced button.

Answer 4

One problem here might be that you are inserting each record line-by-line with SINGLE SQL EXECUTE statements.

Another solution would be:

1. Read the text file into a string buffer (20.000 lines)
2. Create a DataTable object
3. In a loop, insert every line into the DataTable object.
4. Finally, with a DataAdapter, write the DataTable back into the database.