Examples of BulkInsert for PostgreSQL, MySQL and MS SQL using ServiceStack OrmLite. Work in progress...

gistfile1.txt

public static void BulkInsertNpgsql<T>(this IDbConnection dbConn, IEnumerable<T> list, IEnumerable<string> insertFields = null)
        {
      
            if (list == null) return;
            if (list.Count() < 1) return;

            var objWithAttributes = list.FirstOrDefault();
            var modelDef = OrmLiteConfig.GetModelDefinition(objWithAttributes.GetType());

            if (insertFields == null) insertFields = new List<string>();
            var sbColumnNames = new StringBuilder();
            var sbColumnValues = new StringBuilder();

            var targetTableName = "";

            bool isFirstRecord = true;


            var insertFieldsCount = insertFields.Count();
            foreach (var record in list)
            {
                if (isFirstRecord) targetTableName = OrmLiteConfig.DialectProvider.GetQuotedTableName(modelDef);

                var defsCount = modelDef.FieldDefinitions.Count;
                var counter = 0;
                foreach (var fieldDef in modelDef.FieldDefinitions)
                {
                    counter += 1;

                    if (fieldDef.IsComputed) continue;
                    if (fieldDef.AutoIncrement) continue;
                    //insertFields contains Attribute "Name" of fields to insert ( that's how expressions work )
                    if (insertFieldsCount > 0 && !insertFields.Contains(fieldDef.Name)) continue;

                    if (sbColumnNames.Length > 0 && isFirstRecord) sbColumnNames.Append(",");

                    try
                    {
                        if (isFirstRecord) sbColumnNames.Append(OrmLiteConfig.DialectProvider.GetQuotedColumnName(fieldDef.FieldName));

                        var stringValue = "";
                        var value = fieldDef.GetValue(record);
                        if (value == null) stringValue = "\\N";
                        else if (fieldDef.FieldType == typeof(DateTime))
                        {
                            var dateValue = (DateTime)value;
                            const string iso8601Format = "yyyy-MM-dd HH:mm:ss.fff";
                            stringValue = dateValue.ToString(iso8601Format);
                        }
                        else if (fieldDef.FieldType == typeof(Guid))
                        {
                            var guidValue = (Guid)value;
                            stringValue = guidValue.ToString();
                        }
                        else
                        {
                            stringValue = value.ToString();
                        }

                        sbColumnValues.Append(stringValue);

                        if (counter < defsCount)
                        {
                            sbColumnValues.Append("\t");
                        }
                    }
                    catch (Exception ex)
                    {
                        throw;
                    }
                }
                sbColumnValues.Append("\r\n");
                isFirstRecord = false;
            }
            var strColumnValues = sbColumnValues.ToString();
            byte[] byteArrayColumnValues = System.Text.Encoding.UTF8.GetBytes(strColumnValues);
            MemoryStream msColumnValues = new MemoryStream(byteArrayColumnValues);

            //var connection = dbConn as NpgsqlConnection;
            var ormliteConn = dbConn as OrmLiteConnection;
            var connection = ormliteConn.DbConnection as NpgsqlConnection;
            //var connection = (NpgsqlConnection)dbConn.Database.ToDbConnection();
            //var connection = dbConn.DbConnection;

            using (var command = new NpgsqlCommand(string.Format("COPY {0} ({1}) FROM STDIN DELIMITER '\t' ", targetTableName, sbColumnNames), connection))
            {
                var cin = new NpgsqlCopyIn(command, connection, msColumnValues);
                try
                {
                    cin.Start();
                }
                catch (Exception e)
                {
                    try
                    {
                        cin.Cancel("Undo copy");
                    }
                    catch (NpgsqlException e2)
                    {
                        // we should get an error in response to our cancel request:
                        if (!("" + e2).Contains("Undo copy"))
                        {
                            throw new Exception("Failed to cancel copy: " + e2 + " upon failure: " + e);
                        }
                    }
                    throw e;
                }
            }

        }

private static string ToMySqlBulkInsertValue<T>(this FieldDefinition fieldDef, T record)
        {
            var stringValue = "";
            var value = fieldDef.GetValue(record);
            if (value == null) stringValue = "";
            else if (fieldDef.FieldType == typeof(DateTime))
            {
                var dateValue = (DateTime)value;
                const string iso8601Format = "yyyy-MM-dd HH:mm:ss.fff";
                stringValue = dateValue.ToString(iso8601Format);
            }
            else if (fieldDef.FieldType == typeof(Guid))
            {
                var guidValue = (Guid)value;
                stringValue = guidValue.ToString();
            }
            else
            {
                stringValue = value.ToString();
            }
            return stringValue;
        }

        // http://theonetechnologies.com/outsourcing/post/mysql-bulk-data-import-using-net-connector-mysqlbulkloader-class.aspx
        public static void BulkInsertMySql<T>(this IDbConnection myConnection, IEnumerable<T> list/*, IEnumerable<string> insertFields = null*/)
        {
            if (list == null) return;
            if (list.Count() < 1) return;

            var objWithAttributes = list.FirstOrDefault();
            var modelDef = OrmLiteConfig.GetModelDefinition(objWithAttributes.GetType());

            var targetTableName = OrmLiteConfig.DialectProvider.GetQuotedTableName(modelDef);

            var Server = HttpContext.Current.Server;

            string strFile = targetTableName + "_" + 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/"));
            strFile = Server.MapPath("~/TempFolder/") + strFile;
            //If file does not exist then create it and right data into it..
            if (!File.Exists(strFile))
            {
                FileStream fs = new FileStream(strFile, FileMode.Create, FileAccess.Write);
                fs.Close();
                fs.Dispose();
            }

            bool isFirstRecord = true;

            StreamWriter sw = new StreamWriter(strFile, false);

            //var insertFieldsCount = insertFields.Count();
            var defsCount = modelDef.FieldDefinitions.Count;

            foreach (var record in list)
            {
                if (isFirstRecord)
                {
                    sw.Write(string.Join("\t", modelDef.FieldDefinitions.Select(x => x.Name)));
                    sw.Write(sw.NewLine);
                    isFirstRecord = false;
                }

                sw.Write(string.Join("\t", modelDef.FieldDefinitions.Select(x => x.ToMySqlBulkInsertValue<T>(record))));
                sw.Write(sw.NewLine);
            }
            sw.Close();
            sw.Dispose();

            var connection = myConnection as MySqlConnection;
            var bl = new MySqlBulkLoader(connection);
            bl.TableName = targetTableName;
            bl.FieldTerminator = "\t";
            bl.LineTerminator = sw.NewLine;
            bl.FileName = strFile;
            bl.NumberOfLinesToSkip = 1;
            var inserted = bl.Load();

        }

        public static void BulkInsertMsSql<T>(this IDbConnection dbConn, IEnumerable<T> list)
        {
            if (list == null) return;
            if (list.Count() < 1) return;

            var objWithAttributes = list.FirstOrDefault();
            var modelDef = OrmLiteConfig.GetModelDefinition(objWithAttributes.GetType());

            var targetTableName = OrmLiteConfig.DialectProvider.GetQuotedTableName(modelDef);

            using (var bulkCopy = new SqlBulkCopy(dbConn as SqlConnection))
            {
                bulkCopy.BatchSize = list.Count();
                bulkCopy.DestinationTableName = targetTableName;

                var table = new DataTable();

                foreach (var fieldDef in modelDef.FieldDefinitions)
                {
                    if (fieldDef.IsComputed) continue;
                    if (fieldDef.AutoIncrement) continue;

                    bulkCopy.ColumnMappings.Add(fieldDef.Name, fieldDef.Name);
                    table.Columns.Add(fieldDef.Name, Nullable.GetUnderlyingType(fieldDef.FieldType) ?? fieldDef.FieldType);
                }

                foreach (var record in list)
                {
                    //var values = new List<object>();
                    //var dataRows = new List<DataRow>();
                    DataRow row = table.NewRow();
                    foreach (var fieldDef in modelDef.FieldDefinitions)
                    {
                        if (fieldDef.IsComputed) continue;
                        if (fieldDef.AutoIncrement) continue;

                        //values.Add(fieldDef.GetValue(record));
                        //values.Add(SqlServerDialect.Provider.ConvertDbValue(fieldDef.GetValue(record), fieldDef.FieldType));
                        //row.
                        row[fieldDef.Name] = SqlServerDialect.Provider.ConvertDbValue(fieldDef.GetValue(record), fieldDef.FieldType); //Nullable.GetUnderlyingType(fieldDef.FieldType) ?? fieldDef.FieldType;
                    }
                    table.Rows.Add(row);
                    //table.Rows.Add(values);
                }

                bulkCopy.WriteToServer(table);
            }
        }
 

I am getting "Cannot set Column 'foo' to be null. Please use DBNull instead.".

Welcome to the persnippity world of SqlBulkCopy ☹️

Thanks for the examples, is this released under an OSS license?

Yep. OSS. @mythz Feel free to integrate it to OrmLite if needed.

Funny thing that I completely forgot about this Gist and found a link to it on https://forums.servicestack.net/t/how-to-insert-multiple-records-with-1-insert/6494/2 when was googling how to do a bulk insert with OrmLite ;-)

@sharpe5 please also note Postgres Bulk insert API has been changed - http://www.npgsql.org/doc/copy.html
I will try to update the code with your changes and new Bulk Insert API

@zelid Thanks for the update!

When you update the gist can you add the OSS license you're releasing it under e.g. // MIT or if you want to make it freely available you can release it to public domain with // Any copyright is dedicated to the Public Domain..