• .NETCore批量插入数据BulkLoader


    namespace DapperExtensions.MySql
    {
        public static class MySqlBulkLoaderHelper
        {
            /// <summary>
            ///将DataTable转换为标准的CSV
            /// </summary>
            /// <param name="table">数据表</param>
            /// <returns>返回标准的CSV</returns>
            private static string DataTableToCsv(DataTable table)
            {
                //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++)
                    {
                        colum = table.Columns[i];
                        if (i != 0) sb.Append(",");
                        if (colum.DataType == typeof(string) && row[colum].ToString().Contains(","))
                        {
                            sb.Append(""" + row[colum].ToString().Replace(""", """") + """);
                        }
                        else if (colum.DataType == typeof(DateTime) || colum.DataType == typeof(DateTime?))
                        {
                            sb.Append(string.IsNullOrEmpty(row[colum].ToString()) ? "1970-01-01 00:00:00" : row[colum].ToString());
                        }
                        else sb.Append(row[colum].ToString());
                    }
                    sb.AppendLine();
                }
    
    
                return sb.ToString();
            }
    
            /// <summary>
            ///大批量数据插入,返回成功插入行数
            /// </summary>
            /// <param name="connectionString">数据库连接字符串</param>
            /// <param name="table">数据表</param>
            /// <returns>返回成功插入行数</returns>
            public static int BulkInsert(string connectionString, DataTable table)
            {
                if (string.IsNullOrEmpty(table.TableName)) throw new Exception("请给DataTable的TableName属性附上表名称");
                if (table.Rows.Count == 0) return 0;
                int insertCount = 0;
                string tmpPath = Path.GetTempFileName();
                string csv = DataTableToCsv(table);
                File.WriteAllText(tmpPath, csv);
                // MySqlTransaction tran = null;
    
                using (MySqlConnection conn = new MySqlConnection(connectionString))
                {
                    try
                    {
                        conn.Open();
                        //tran = conn.BeginTransaction();
                        MySqlBulkLoader bulk = new MySqlBulkLoader(conn)
                        {
                            FieldTerminator = ",",
                            FieldQuotationCharacter = '"',
                            EscapeCharacter = '"',
                            LineTerminator = "
    ",
                            FileName = tmpPath,
                            NumberOfLinesToSkip = 0,
                            TableName = table.TableName,
                        };
                        //bulk.Columns.AddRange(table.Columns.Cast<DataColumn>().Select(colum => colum.ColumnName).ToArray());
                        insertCount = bulk.Load();
                        // tran.Commit();
                    }
                    catch (MySqlException ex)
                    {
                        // if (tran != null) tran.Rollback();
                        File.Delete(tmpPath);
                        throw ex;
                    }
                }
                File.Delete(tmpPath);
                return insertCount;
            }
        }
    }
    

      MSSQL有SqlBulkCopy,MYSQL有MySqlBulkLoader,Oracle有OracleBulkCopy,对应各自的驱动。

      但是core没有批量插入数据的方法,所以只能创建临时CSV,导入CSV,批量插入后再删除CSV

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  • 原文地址:https://www.cnblogs.com/yinzhou/p/11093033.html
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