详解MySqlBulkLoader的使用

using System;
using System.Collections.Generic;
namespace MySqlBulkLoaderDemo
{
    class Program
    {
        static void Main(string[] args)
        {
            //装载30个数据
            List<Student> stuList = new List<Student>();
            for (int i = 0; i < 30; i++)
            {
                stuList.Add(
                new Student
                {
                    Guid = Guid.NewGuid().ToString(),
                    Name = "QXH",
                    Age = new Random().Next(1, 30)
                });
            }
            //调用MySqlBulkLoader，往student表中插入stuList
            int insertCount = MySqlBulkLoaderHelper.BulkInsert<Student>(stuList, "student");
            Console.WriteLine($"成功插入{insertCount}条数据");
            Console.ReadKey();
        }
    }
}

using System;
using System.Collections.Generic;
using System.Text;

namespace MySqlBulkLoaderDemo
{
    public class Student
    {
        public string Guid { get; set; }
        public string Name { get; set; }
        public int Age { get; set; }
    }
}

using MySql.Data.MySqlClient;
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations.Schema;
using System.Data;
using System.IO;
using System.Linq;
using System.Text;

namespace MySqlBulkLoaderDemo
{
    public class MySqlBulkLoaderHelper
    {
        const string ConnectionString = "server=localhost;port=3306;user=root;passWord=123456;database=mysql;SslMode = none;AllowLoadLocalInfile=true";
        public static int BulkInsert<T>(List<T> entities, string tableName)
        {
            DataTable dt = entities.ToDataTable();
            using (MySqlConnection conn = new MySqlConnection())
            {
                conn.ConnectionString = ConnectionString;
                if (conn.State != ConnectionState.Open)
                {
                    conn.Open();
                }

                if (tableName.IsNullOrEmpty())
                {
                    var tableAttribute = typeof(T).GetCustomAttributes(typeof(TableAttribute), true).FirstOrDefault();
                    if (tableAttribute != null)
                        tableName = ((TableAttribute)tableAttribute).Name;
                    else
                        tableName = typeof(T).Name;
                }

                int insertCount = 0;
                string tmpPath = Path.Combine(Path.GetTempPath(), DateTime.Now.Ticks.ToString() + "_" + Guid.NewGuid().ToString() + ".tmp");
                string csv = dt.ToCsvStr();
                File.WriteAllText(tmpPath, csv, Encoding.UTF8);

                using (MySqlTransaction tran = conn.BeginTransaction())
                {
                    MySqlBulkLoader bulk = new MySqlBulkLoader(conn)
                    {
                        FieldTerminator = ",",
                        FieldQuotationCharacter = '"',
                        EscapeCharacter = '"',
                        LineTerminator = "\r\n",
                        FileName = tmpPath,
                        Local = true,
                        NumberOfLinesToSkip = 0,
                        TableName = tableName,
                        CharacterSet = "utf8"
                    };
                    try
                    {
                        bulk.Columns.AddRange(dt.Columns.Cast<DataColumn>().Select(colum => colum.ColumnName).ToList());
                        insertCount = bulk.Load();
                        tran.Commit();
                    }
                    catch (MySqlException ex)
                    {
                        if (tran != null)
                            tran.Rollback();

                        throw ex;
                    }
                }
                File.Delete(tmpPath);
                return insertCount;
            }

        }
    }
}

using Newtonsoft.JSON;
using System;
using System.Collections.Generic;
using System.Data;
using System.Text;

namespace MySqlBulkLoaderDemo
{
    public static class ExtentionHelper
    {
        /// <summary>
        /// 将对象序列化成json字符串
        /// </summary>
        /// <param name="obj">需要序列化的对象</param>
        /// <returns></returns>
        public static string ToJson(this object obj)
        {
            return JsonConvert.SerializeObject(obj);
        }
        /// <summary>
        /// 将Json字符串转为DataTable
        /// </summary>
        /// <param name="jsonStr">Json字符串</param>
        /// <returns></returns>
        public static DataTable ToDataTable(this string jsonStr)
        {
            return jsonStr == null ? null : JsonConvert.DeserializeObject<DataTable>(jsonStr);
        }
        /// <summary>
        /// 将IEnumerable'T'转为对应的DataTable
        /// </summary>
        /// <typeparam name="T">数据模型</typeparam>
        /// <param name="iEnumberable">数据源</param>
        /// <returns>DataTable</returns>
        public static DataTable ToDataTable<T>(this IEnumerable<T> iEnumberable)
        {
            return iEnumberable.ToJson().ToDataTable();
        }
        /// <summary>
        /// 判断是否为Null或者空
        /// </summary>
        /// <param name="obj">对象</param>
        /// <returns></returns>
        public static bool IsNullOrEmpty(this object obj)
        {
            if (obj == null)
                return true;
            else
            {
                string objStr = obj.ToString();
                return string.IsNullOrEmpty(objStr);
            }
        }

        /// <summary>
        ///将DataTable转换为标准的CSV字符串
        /// </summary>
        /// <param name="dt">数据表</param>
        /// <returns>返回标准的CSV</returns>
        public static string ToCsvStr(this DataTable dt)
        {
            //以半角逗号（即,）作分隔符，列为空也要表达其存在。
            //列内容如存在半角逗号（即,）则用半角引号（即""）将该字段值包含起来。
            //列内容如存在半角引号（即"）则应替换成半角双引号（""）转义，并用半角引号（即""）将该字段值包含起来。
            StringBuilder sb = new StringBuilder();
            DataColumn colum;
            foreach (DataRow row in dt.Rows)
            {
                for (int i = 0; i < dt.Columns.Count; i++)
                {
                    colum = dt.Columns[i];
                    if (i != 0) sb.Append(",");
                    if (colum.DataType == typeof(string) && row[colum].ToString().Contains(","))
                    {
                        sb.Append("\"" + row[colum].ToString().Replace("\"", "\"\"") + "\"");
                    }
                    else sb.Append(row[colum].ToString());
                }
                sb.AppendLine();
            }

            return sb.ToString();
        }
    }
}

SET GLOBAL local_infile=1；//1表示开启，0表示关闭

SHOW VARIABLES LIKE '%local%';

System.NotSupportedException
HResult=0x80131515
Message=To use MySqlBulkLoader.Local=true, set AllowLoadLocalInfile=true in the connection string. See https://fl.vu/mysql-load-data