Steps for importing tens of millions of data into MySQL using .Net Core

CREATE TABLE `trade` (
  `id` VARCHAR(50) NULL DEFAULT NULL COLLATE 'utf8_unicode_ci',
  `trade_no` VARCHAR(50) NULL DEFAULT NULL COLLATE 'utf8_unicode_ci',
  UNIQUE INDEX `id` (`id`),
  INDEX `trade_no` (`trade_no`)
)
COMMENT = 'Order'
COLLATE='utf8_unicode_ci'
ENGINE=InnoDB;

//Start time var startTime = DateTime.Now;
using (var conn = new MySqlConnection(connsql))
{
    conn.Open();
​
    //Insert 100,000 data for (var i = 0; i < 100000; i++)
    {
        //Insert var sql = string.Format("insert into trade(id,trade_no) values('{0}','{1}');",
            Guid.NewGuid().ToString(), "trade_" + (i + 1)
            );
        var sqlComm = new MySqlCommand();
        sqlComm.Connection = conn;
        sqlComm.CommandText = sql;
        sqlComm.ExecuteNonQuery();
        sqlComm.Dispose();
    }
​
    conn.Close();
}
​
//Completion time var endTime = DateTime.Now;
​
//Time consuming var spanTime = endTime - startTime;
Console.WriteLine("Loop insertion method takes: " + spanTime.Minutes + "minutes" + spanTime.Seconds + "seconds" + spanTime.Milliseconds + "milliseconds");

//Start time var startTime = DateTime.Now;
using (var conn = new MySqlConnection(connsql))
{
    conn.Open();
​
    //Insert 100,000 data var sql = new StringBuilder();
    for (var i = 0; i < 100000; i++)
    {
        //Insert sql.AppendFormat("insert into trade(id,trade_no) values('{0}','{1}');",
            Guid.NewGuid().ToString(), "trade_" + (i + 1)
            );
​
        //Merge and insert if (i % 1000 == 999)
        {
            var sqlComm = new MySqlCommand();
            sqlComm.Connection = conn;
            sqlComm.CommandText = sql.ToString();
            sqlComm.ExecuteNonQuery();
            sqlComm.Dispose();
            sql.Clear();
        }
    }
​
    conn.Close();
}
​
//Completion time var endTime = DateTime.Now;
​
//Time consuming var spanTime = endTime - startTime;
Console.WriteLine("Loop insertion method takes: " + spanTime.Minutes + "minutes" + spanTime.Seconds + "seconds" + spanTime.Milliseconds + "milliseconds");

//Start time var startTime = DateTime.Now;
using (var conn = new MySqlConnection(connsql))
{
    conn.Open();
​
    //Insert 100,000 data var sql = new StringBuilder();
    for (var i = 0; i < 100000; i++)
    {
        if (i % 1000 == 0)
        {
            sql.Append("insert into trade(id,trade_no) values");
        }
​
        // concatenation sql.AppendFormat("('{0}','{1}'),", Guid.NewGuid().ToString(), "trade_" + (i + 1));
​
        //Insert 1000 records at a time if (i % 1000 == 999)
        {
            var sqlComm = new MySqlCommand();
            sqlComm.Connection = conn;
            sqlComm.CommandText = sql.ToString().TrimEnd(',');
            sqlComm.ExecuteNonQuery();
            sqlComm.Dispose();
            sql.Clear();
        }
    }

        ​
    conn.Close();
}
​
//Completion time var endTime = DateTime.Now;
​
//Time consuming var spanTime = endTime - startTime;
Console.WriteLine("Merge data insertion method takes time: " + spanTime.Minutes + "minutes" + spanTime.Seconds + "seconds" + spanTime.Milliseconds + "milliseconds");

//Start time var startTime = DateTime.Now;
using (var conn = new MySqlConnection(connsql))
{
    conn.Open();
    var table = new DataTable();
    table.Columns.Add("id", typeof(string));
    table.Columns.Add("trade_no", typeof(string));
​
    //Generate 100,000 data for (var i = 0; i < 100000; i++)
    {
        if (i % 500000 == 0)
        {
            table.Rows.Clear();
        }
​
        //Record var row = table.NewRow();
        row[0] = Guid.NewGuid().ToString();
        row[1] = "trade_" + (i + 1);
        table.Rows.Add(row);
​
        //Insert 500,000 records in a batch if (i % 500000 != 499999 && i < (100000 - 1))
        {
            continue;
        }
        Console.WriteLine("Start inserting: " + i);
​
        //Convert data to csv format var tradeCsv = DataTableToCsv(table);
        var tradeFilePath = System.AppDomain.CurrentDomain.BaseDirectory + "trade.csv";
        File.WriteAllText(tradeFilePath, tradeCsv);
​
        #region Save to database var bulkCopy = new MySqlBulkLoader(conn)
        {
            FieldTerminator = ",",
            FieldQuotationCharacter = '"',
            EscapeCharacter = '"',
            LineTerminator = "\r\n",
            FileName = tradeFilePath,
            NumberOfLinesToSkip = 0,
            TableName = "trade"
        };
​
        bulkCopy.Columns.AddRange(table.Columns.Cast<DataColumn>().Select(colum => colum.ColumnName).ToList());
        bulkCopy.Load();
        #endregion
    }
​
    conn.Close();
}
​
//Completion time var endTime = DateTime.Now;
​
//Time consuming var spanTime = endTime - startTime;
Console.WriteLine("MySqlBulk method takes: " + spanTime.Minutes + "minutes" + spanTime.Seconds + "seconds" + spanTime.Milliseconds + "milliseconds");