最近在项目中遇到插入几万、几十万、几百万的数据到MYSQL数据库，使用EF插入会发现插入速度非常慢的场景，
数据量非常大时EF插入需要几十分钟，甚至几个小时，这样子的速度肯定不是我们所期望的。
后面经过了解与研究发现MySqlBulkLoader，可以批量将数据插入到数据库并且速度上面远远优于EF。
MySqlBulkLoader主要的实现方式：将需要插入的数据转成DataTable，转成一个CSV文件，将CSV文件使用批量导入的形式导入到数据库里面去。
注意：
1.数据库连接地址需要添加配置AllowLoadLocalInfile=true,允许本地文件导入；
Data Source = 数据库地址; Port = 端口; Initial Catalog = 数据库名; User Id = 用户名; Password = 密码;AllowLoadLocalInfile=true;
2.插入的时候会返回插入行数，但是检查所有的数据都正确，也没有报异常，却返回了插入数量为0，可以检查表是否有唯一索引，插入的数据是否违反了唯一索引。
（以下分块展示了代码，如果需要看完整的代码直接看 5.完整的代码）
1.将List转化为DataTable
/// <summary> /// 将List转化为DataTable /// </summary> /// <returns></returns> public DataTable ListToDataTable<T>(List<T> data) { #region 创建一个DataTable，以实体名称作为DataTable名称 var tableName = typeof(T).Name; tableName = tableName.ToSnakeCase(); /*实体名称与表名进行转化，主要根据各项目的规定进行转化,不一定就是我这些写的这种转换方式*/ DataTable dt = new DataTable { TableName = tableName }; #endregion #region 拿取列名，以实体的属性名作为列名 var properties = typeof(T).GetProperties(); foreach (var item in properties) { var curFileName = item.Name; curFileName = curFileName.ToSnakeCase();/*列名与表名进行转化，主要根据各项目的规定进行转化,不一定就是我这些写的这种转换方式*/ dt.Columns.Add(curFileName); } #endregion #region 列赋值 foreach (var item in data) { DataRow dr = dt.NewRow(); var columns = dt.Columns; var curPropertyList = item.GetType().GetProperties(); foreach (var p in curPropertyList) { var name = p.Name; name = name.ToSnakeCase();/*列名与表名进行转化，主要根据各项目的规定进行转化,不一定就是我这些写的这种转换方式*/ var curValue = p.GetValue(item); int i = columns.IndexOf(name); dr[i] = curValue; } dt.Rows.Add(dr); } #endregion return dt; }
2.将DataTable转换为标准的CSV文件
/// <summary> /// csv扩展 /// </summary> public static class CSVEx { /// <summary> ///将DataTable转换为标准的CSV文件 /// </summary> /// <param name="table">数据表</param> /// <param name="tmpPath">文件地址</param> /// <returns>返回标准的CSV</returns> public static void ToCsv(this DataTable table, string tmpPath) { //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 table.Rows) { for (int i = 0; i < table.Columns.Count; i++) { Type _datatype = typeof(DateTime); colum = table.Columns[i]; if (i != 0) sb.Append("\t"); //if (colum.DataType == typeof(string) && row[colum].ToString().Contains(",")) //{ // sb.Append("\"" + row[colum].ToString().Replace("\"", "\"\"") + "\""); //} if (colum.DataType == _datatype) { sb.Append(((DateTime)row[colum]).ToString("yyyy/MM/dd HH:mm:ss")); } else sb.Append(row[colum].ToString()); } sb.Append("\r\n"); } StreamWriter sw = new StreamWriter(tmpPath, false, UTF8Encoding.UTF8); sw.Write(sb.ToString()); sw.Close(); } }
3.CSV文件导入数据到数据库
/// <summary> /// 批量导入mysql帮助类 /// </summary> public static class MySqlHelper { /// <summary> /// MySqlBulkLoader批量导入 /// </summary> /// <param name="_mySqlConnection">数据库连接地址</param> /// <param name="table"></param> /// <param name="csvName"></param> /// <returns></returns> public static int BulkLoad(MySqlConnection _mySqlConnection, DataTable table, string csvName) { var columns = table.Columns.Cast<DataColumn>().Select(colum => colum.ColumnName).ToList(); MySqlBulkLoader bulk = new MySqlBulkLoader(_mySqlConnection) { FieldTerminator = "\t", FieldQuotationCharacter = '"', EscapeCharacter = '"', LineTerminator = "\r\n", FileName = csvName, NumberOfLinesToSkip = 0, TableName = table.TableName, }; bulk.Columns.AddRange(columns); return bulk.Load(); } }
4.使用MySqlBulkLoader批量插入数据
/// <summary> /// 使用MySqlBulkLoader批量插入数据 /// </summary> /// <typeparam name="T"></typeparam> /// <param name="data"></param> /// <returns></returns> /// <exception cref="Exception"></exception> public int BulkLoaderData<T>(List<T> data) { if (data.Count <= 0) return 0; var connectString = "数据库连接地址"; using (MySqlConnection connection = new MySqlConnection(connectString)) { MySqlTransaction sqlTransaction = null; try { if (connection.State == ConnectionState.Closed) { connection.Open(); } sqlTransaction = connection.BeginTransaction(); var dt = ListToDataTable<T>(data); //将List转成dataTable string tmpPath = Path.GetTempFileName(); dt.ToCsv(tmpPath); //将DataTable转成CSV文件 var insertCount = MySqlHelper.BulkLoad(connection, dt, tmpPath); //使用MySqlBulkLoader插入数据 sqlTransaction.Commit(); try { if (File.Exists(tmpPath)) File.Delete(tmpPath); } catch (Exception) { //删除文件失败 } return insertCount; //返回执行成功的条数 } catch (Exception e) { if (sqlTransaction != null) { sqlTransaction.Rollback(); } //执行异常 throw e; } } }
5.完整的代码：
namespace WebApplication1.BrantchInsert { /// <summary> /// 批量插入 /// </summary> public class BulkLoader { /// <summary> /// 测试批量插入入口 /// </summary> /// <returns></returns> public int BrantchDataTest() { #region 模拟数据 var data = new List<CrmCouponTestDto>() { new CrmCouponTestDto { Id=1, CouponCode="test001", CouponId = 1, MemberId=100, IssueTime=Convert.ToDateTime("2022-06-27 14:00:00"), UsageTime=Convert.ToDateTime("3000-12-31 00:00:00"), UsageShopId=0, UsageBillNo="", EffectiveStart=Convert.ToDateTime("2022-06-27 14:00:00"), EffectiveEnd=Convert.ToDateTime("2023-06-27 14:00:00"), Status=0 }, new CrmCouponTestDto { Id=2, CouponCode="test002", CouponId = 1, MemberId=101, IssueTime=Convert.ToDateTime("2022-06-27 14:00:00"), UsageTime=Convert.ToDateTime("2022-06-27 14:30:00"), UsageShopId=2, UsageBillNo="CS202206271430001", EffectiveStart=Convert.ToDateTime("2022-06-27 14:00:00"), EffectiveEnd=Convert.ToDateTime("2023-06-27 14:00:00"), Status=1 }, new CrmCouponTestDto { Id=3, CouponCode="test003", CouponId = 1, MemberId=102, IssueTime=Convert.ToDateTime("2022-06-27 14:00:00"), UsageTime=Convert.ToDateTime("3000-12-31 00:00:00"), UsageShopId=0, UsageBillNo="", EffectiveStart=Convert.ToDateTime("2022-06-27 14:00:00"), EffectiveEnd=Convert.ToDateTime("2023-06-27 14:00:00"), Status=0 }, new CrmCouponTestDto { Id=4, CouponCode="test004", CouponId = 1, MemberId=103, IssueTime=Convert.ToDateTime("2022-06-27 14:00:00"), UsageTime=Convert.ToDateTime("3000-12-31 00:00:00"), UsageShopId=0, UsageBillNo="", EffectiveStart=Convert.ToDateTime("2022-06-27 14:00:00"), EffectiveEnd=Convert.ToDateTime("2023-06-27 14:00:00"), Status=0 } }; #endregion var result = BulkLoaderData<CrmCouponTestDto>(data); return result; } /// <summary> /// 使用MySqlBulkLoader批量插入数据 /// </summary> /// <typeparam name="T"></typeparam> /// <param name="data"></param> /// <returns></returns> /// <exception cref="Exception"></exception> public int BulkLoaderData<T>(List<T> data) { if (data.Count <= 0) return 0; var connectString = "数据库连接地址"; using (MySqlConnection connection = new MySqlConnection(connectString)) { MySqlTransaction sqlTransaction = null; try { if (connection.State == ConnectionState.Closed) { connection.Open(); } sqlTransaction = connection.BeginTransaction(); var dt = ListToDataTable<T>(data); //将List转成dataTable string tmpPath = Path.GetTempFileName(); dt.ToCsv(tmpPath); //将DataTable转成CSV文件 var insertCount = MySqlHelper.BulkLoad(connection, dt, tmpPath); //使用MySqlBulkLoader插入数据 sqlTransaction.Commit(); try { if (File.Exists(tmpPath)) File.Delete(tmpPath); } catch (Exception) { //删除文件失败 } return insertCount; //返回执行成功的条数 } catch (Exception e) { if (sqlTransaction != null) { sqlTransaction.Rollback(); } //执行异常 throw e; } } } /// <summary> /// 将List转化为DataTable核心方法 /// </summary> /// <returns></returns> public DataTable ListToDataTable<T>(List<T> data) { #region 创建一个DataTable，以实体名称作为DataTable名称 var tableName = typeof(T).Name; tableName = tableName.ToSnakeCase(); /*实体名称与表名进行转化，主要根据各项目的规定进行转化,不一定就是我这些写的这种转换方式*/ DataTable dt = new DataTable { TableName = tableName }; #endregion #region 拿取列名，以实体的属性名作为列名 var properties = typeof(T).GetProperties(); foreach (var item in properties) { var curFileName = item.Name; curFileName = curFileName.ToSnakeCase();/*列名与表名进行转化，主要根据各项目的规定进行转化,不一定就是我这些写的这种转换方式*/ dt.Columns.Add(curFileName); } #endregion #region 列赋值 foreach (var item in data) { DataRow dr = dt.NewRow(); var columns = dt.Columns; var curPropertyList = item.GetType().GetProperties(); foreach (var p in curPropertyList) { var name = p.Name; name = name.ToSnakeCase();/*列名与表名进行转化，主要根据各项目的规定进行转化,不一定就是我这些写的这种转换方式*/ var curValue = p.GetValue(item); int i = columns.IndexOf(name); dr[i] = curValue; } dt.Rows.Add(dr); } #endregion return dt; } } /// <summary> /// 批量导入mysql帮助类 /// </summary> public static class MySqlHelper { /// <summary> /// MySqlBulkLoader批量导入 /// </summary> /// <param name="_mySqlConnection">数据库连接地址</param> /// <param name="table"></param> /// <param name="csvName"></param> /// <returns></returns> public static int BulkLoad(MySqlConnection _mySqlConnection, DataTable table, string csvName) { var columns = table.Columns.Cast<DataColumn>().Select(colum => colum.ColumnName).ToList(); MySqlBulkLoader bulk = new MySqlBulkLoader(_mySqlConnection) { FieldTerminator = "\t", FieldQuotationCharacter = '"', EscapeCharacter = '"', LineTerminator = "\r\n", FileName = csvName, NumberOfLinesToSkip = 0, TableName = table.TableName, }; bulk.Columns.AddRange(columns); return bulk.Load(); } } /// <summary> /// csv扩展 /// </summary> public static class CSVEx { /// <summary> ///将DataTable转换为标准的CSV文件 /// </summary> /// <param name="table">数据表</param> /// <param name="tmpPath">文件地址</param> /// <returns>返回标准的CSV</returns> public static void ToCsv(this DataTable table, string tmpPath) { //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 table.Rows) { for (int i = 0; i < table.Columns.Count; i++) { Type _datatype = typeof(DateTime); colum = table.Columns[i]; if (i != 0) sb.Append("\t"); //if (colum.DataType == typeof(string) && row[colum].ToString().Contains(",")) //{ // sb.Append("\"" + row[colum].ToString().Replace("\"", "\"\"") + "\""); //} if (colum.DataType == _datatype) { sb.Append(((DateTime)row[colum]).ToString("yyyy/MM/dd HH:mm:ss")); } else sb.Append(row[colum].ToString()); } sb.Append("\r\n"); } StreamWriter sw = new StreamWriter(tmpPath, false, UTF8Encoding.UTF8); sw.Write(sb.ToString()); sw.Close(); } } /// <summary> /// 字符串转化 /// </summary> public static class StringExtensions { /// <summary> /// 转换为 main_keys_id 这种形式的字符串方式 /// </summary> public static string ToSnakeCase(this string input) { if (string.IsNullOrEmpty(input)) { return input; } var startUnderscores = Regex.Match(input, @"^_+"); return startUnderscores + Regex.Replace(input, @"([a-z0-9])([A-Z])", "$1_$2").ToLower(); } } /// <summary> /// 实体 /// </summary> public class CrmCouponTestDto { /// <summary> /// ID /// </summary> public long Id { get; set; } /// <summary> /// 卡券号 /// </summary> public string CouponCode { get; set; } /// <summary> /// 卡券ID /// </summary> public int CouponId { get; set; } /// <summary> /// 会员ID /// </summary> public int MemberId { get; set; } /// <summary> /// 发放时间 /// </summary> public DateTime IssueTime { get; set; } /// <summary> /// 使用时间 /// </summary> public DateTime UsageTime { get; set; } /// <summary> /// 使用店铺ID /// </summary> public int UsageShopId { get; set; } /// <summary> /// 使用单号 /// </summary> public string UsageBillNo { get; set; } /// <summary> /// 有效开始时间 /// </summary> public DateTime EffectiveStart { get; set; } /// <summary> /// 有效结束时间 /// </summary> public DateTime EffectiveEnd { get; set; } /// <summary> /// 状态 /// CouponStatus 卡券状态: /// -1：未领用 /// 0：未使用 /// 1：已使用 /// 2：已过期 ///3：已作废 ///4：转赠中 /// </summary> public Int16 Status { get; set; } } }