MySQL - Bulk data import using .Net connector MySqlBulkLoader Class

最新推荐文章于 2020-01-18 16:18:41 发布

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最新推荐文章于 2020-01-18 16:18:41 发布

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文章标签：数据库

本文介绍如何使用MySQL .Net连接器及MySqlBulkLoader类从DataTable创建.csv文件，并批量导入MySQL数据库。文中提供了完整的C#代码示例，包括创建.csv文件、定义DataTable结构和使用MySqlBulkLoader进行数据导入。

Lets see how do we import bulk data in MySQL database? To deal with MySQL database we first need MySQL to .Net connector, which can be downloaded from here. When you install this connector, it will give you DLLs required to deal with MySQL database from .Net code.

Reference MySql.Data.dll in your .Net project, we'll be using MySqlBulkLoader class to import bulk data. However this class doesn't provide any direct way to load DataTable into database, but it provides way to bulk load .csv file.

1. Function to create .csv file from DataTable (you can skip this, if you already have csv file)

public static void CreateCSVfile(DataTable dtable, string strFilePath)
{
    StreamWriter sw = new StreamWriter(strFilePath, false);
    int icolcount = dtable.Columns.Count;
    foreach (DataRow drow in dtable.Rows)
    {
    for (int i = 0; i < icolcount; i++)
    {
        if (!Convert.IsDBNull(drow[i]))
        {
        sw.Write(drow[i].ToString());
        }
        if (i < icolcount - 1)
        {
        sw.Write(",");
        }
    }
    sw.Write(sw.NewLine);
    }
    sw.Close();
    sw.Dispose();
}

2. Import data into MySQL database

private void ImportMySQL()
{
    DataTable orderDetail = new DataTable("ItemDetail");
    DataColumn c = new DataColumn();        // always
    orderDetail.Columns.Add(new DataColumn("ID", Type.GetType("System.Int32")));
    orderDetail.Columns.Add(new DataColumn("value", Type.GetType("System.Int32")));
    orderDetail.Columns.Add(new DataColumn("length", Type.GetType("System.Int32")));
    orderDetail.Columns.Add(new DataColumn("breadth", Type.GetType("System.Int32")));
    orderDetail.Columns.Add(new DataColumn("total", Type.GetType("System.Decimal")));
    orderDetail.Columns["total"].Expression = "value/(length*breadth)";
 
    //Adding dummy entries
    DataRow dr = orderDetail.NewRow();
    dr["ID"] = 1;
    dr["value"] = 50;
    dr["length"] = 5;
    dr["breadth"] = 8;
    orderDetail.Rows.Add(dr);
 
    dr = orderDetail.NewRow();
    dr["ID"] = 2;
    dr["value"] = 60;
    dr["length"] = 15;
    dr["breadth"] = 18;
    orderDetail.Rows.Add(dr);
    //Adding dummy entries
 
    string connectMySQL = "Server=localhost;Database=test;Uid=username;Pwd=password;";
    string strFile = "/TempFolder/MySQL" + DateTime.Now.Ticks.ToString() + ".csv";
 
    //Create directory if not exist... Make sure directory has required rights..
    if (!Directory.Exists(Server.MapPath("~/TempFolder/")))
    Directory.CreateDirectory(Server.MapPath("~/TempFolder/"));
 
    //If file does not exist then create it and right data into it..
    if (!File.Exists(Server.MapPath(strFile)))
    {
    FileStream fs = new FileStream(Server.MapPath(strFile), FileMode.Create, FileAccess.Write);
    fs.Close();
    fs.Dispose();
    }
 
    //Generate csv file from where data read
    CreateCSVfile(orderDetail, Server.MapPath(strFile));
    using (MySqlConnection cn1 = new MySqlConnection(connectMySQL))
    {
    cn1.Open();
    MySqlBulkLoader bcp1 = new MySqlBulkLoader(cn1);
    bcp1.TableName = "productorder"; //Create ProductOrder table into MYSQL database...
    bcp1.FieldTerminator = ",";
 
    bcp1.LineTerminator = "\r\n";
    bcp1.FileName = Server.MapPath(strFile);
    bcp1.NumberOfLinesToSkip = 0;
    bcp1.Load();
 
    //Once data write into db then delete file..
    try
    {
        File.Delete(Server.MapPath(strFile));
    }
    catch (Exception ex)
    {
        string str = ex.Message;
    }
    }
}