/// RemoteConnection Quick Start client example.
        /// Creates a Connection to a remote database using a proxy.
        /// </summary>
        /// <returns>The connection to the remote database</returns>
        /// <exception cref="AceQLException">If any Exception occurs.</exception>
        public static AceQLConnection RemoteConnectionBuilderUsingProxyAsync()
        {
            // Port number is the port number used to start the Web Server:
            string server   = "http://www.aceql.com:9090/aceql";
            string database = "sampledb";

            // (username, password) for authentication on server side.
            // No authentication will be done for our Quick Start:
            string username = "******";
            string password = "******";

            // WebProxy will be detected, pass the auth info for proxy that require authentication:
            string proxyUri      = "http://localhost:8080";
            string proxyUsername = "******";
            string proxyPassword = null;

            String   path     = AceQLConnection.GetAceQLLocalFolder() + "\\password.txt";
            FileInfo fileInfo = new FileInfo(path);

            if (fileInfo.Exists)
            {
                proxyPassword = File.ReadAllText(path);
            }

            string connectionString = $"Server={server}; Database={database}; "
                                      + $"Username={username}; Password={password};"
                                      + $"ProxyUri={proxyUri};"
                                      + $"ProxyUsername={proxyUsername}; ProxyPassword={proxyPassword}";

            AceQLConnection connection = new AceQLConnection(connectionString);

            return(connection);
        }
        /// <summary>
        /// Executes our example using an <see cref="AceQLConnection"/>
        /// </summary>
        /// <param name="connection"></param>
        public static async Task ExecuteExample(AceQLConnection connection)
        {
            await connection.OpenAsync();

            AceQLConsole.WriteLine("Host: " + connection.ConnectionInfo.ConnectionString);
            AceQLConsole.WriteLine("aceQLConnection.GetClientVersion(): " + AceQLConnection.GetClientVersion());
            AceQLConsole.WriteLine("aceQLConnection.GetServerVersion(): " + await connection.GetServerVersionAsync());
            AceQLConsole.WriteLine("AceQL local folder: ");
            AceQLConsole.WriteLine(AceQLConnection.GetAceQLLocalFolder());

            int maxSelect = 1;

            for (int j = 0; j < maxSelect; j++)
            {
                string       sql     = "select * from customer where customer_id > @parm1 and lname = @parm2";
                AceQLCommand command = new AceQLCommand(sql, connection);

                command.Parameters.AddWithValue("@parm2", "Name_5");
                command.Parameters.AddWithValue("@parm1", 1);

                // Our dataReader must be disposed to delete underlying downloaded files
                using (AceQLDataReader dataReader = await command.ExecuteReaderAsync())
                {
                    //await dataReader.ReadAsync(new CancellationTokenSource().Token)
                    while (dataReader.Read())
                    {
                        AceQLConsole.WriteLine();
                        AceQLConsole.WriteLine("" + DateTime.Now);
                        int i = 0;
                        AceQLConsole.WriteLine("GetValue: " + dataReader.GetValue(i++) + "\n"
                                               + "GetValue: " + dataReader.GetValue(i++) + "\n"
                                               + "GetValue: " + dataReader.GetValue(i++) + "\n"
                                               + "GetValue: " + dataReader.GetValue(i++) + "\n"
                                               + "GetValue: " + dataReader.GetValue(i++) + "\n"
                                               + "GetValue: " + dataReader.GetValue(i++) + "\n"
                                               + "GetValue: " + dataReader.GetValue(i++) + "\n"
                                               + "GetValue: " + dataReader.GetValue(i));
                    }
                }
            }
        }
        private async void buttonSelectBlob_ClickAsync(object sender, EventArgs e)
        {
            if (connection == null)
            {
                PopMesssage.Show("Please connect to remote database before Select!", ACEQL_TEST);
                return;
            }

            Cursor.Current = Cursors.WaitCursor;
            try
            {
                string folder = AceQLConnection.GetAceQLLocalFolder();
                String file   = folder + "\\koala_blob.jpg";

                RemoteStatement remoteStatement = new RemoteStatement(connection);

                using (Stream stream = await remoteStatement.SelectProductImageAsync(1))
                {
                    if (stream == null)
                    {
                        PopMesssage.Show("Click \"Insert\" to insert a Blob in remote database before doing the Select!", ACEQL_TEST);
                        return;
                    }

                    // Dump on koala_blob.jpg
                    using (var writeStream = File.OpenWrite(file))
                    {
                        stream.CopyTo(writeStream);
                    }
                }

                PopMesssage.Show("Blob successfully downloaded from database in file: \n"
                                 + file, ACEQL_TEST);
            }
            catch (Exception exeption)
            {
                Cursor.Current = Cursors.Default;
                PopMesssage.Show("Could not execute Insert statement: \n" + exeption.ToString(), ACEQL_TEST);
            }
            Cursor.Current = Cursors.Default;
        }
        private async void buttonInsertBlob_ClickAsync(object sender, EventArgs e)
        {
            if (connection == null)
            {
                PopMesssage.Show("Please connect to remote database before Insert!", ACEQL_TEST);
                return;
            }

            // Test if koala.jpg is in ACEQL_PCL_FOLDER

            String folder = AceQLConnection.GetAceQLLocalFolder();
            String file   = folder + "\\koala.jpg";

            if (!File.Exists(file))
            {
                PopMesssage.Show("Please copy a file named koala.jpg in this folder and try again: \n"
                                 + folder
                                 , ACEQL_TEST);
                return;
            }

            Cursor.Current = Cursors.WaitCursor;
            try
            {
                // Delte all before to avoid duplicates
                RemoteStatement remoteStatement = new RemoteStatement(connection);
                await remoteStatement.DeleteAllProductsAsync();

                Stream stream = File.OpenRead(file);
                await remoteStatement.InsertIntoProductAsync(1, "koala.jpg", stream);

                PopMesssage.Show("Blob inserted in database!", ACEQL_TEST);
            }
            catch (Exception exeption)
            {
                Cursor.Current = Cursors.Default;
                PopMesssage.Show("Could not execute Insert statement: \n" + exeption.ToString(), ACEQL_TEST);
            }
            Cursor.Current = Cursors.Default;
        }
        /// <summary>
        /// Executes our example using an <see cref="AceQLConnection"/>
        /// </summary>
        /// <param name="connection"></param>
        private static async Task ExecuteExample(AceQLConnection connection)
        {
            await connection.OpenAsync();

            AceQLConsole.WriteLine("host: " + connection.ConnectionInfo.ConnectionString);
            AceQLConsole.WriteLine("aceQLConnection.GetClientVersion(): " + AceQLConnection.GetClientVersion());
            AceQLConsole.WriteLine("aceQLConnection.GetServerVersion(): " + await connection.GetServerVersionAsync());
            AceQLConsole.WriteLine("AceQL local folder: ");
            AceQLConsole.WriteLine(AceQLConnection.GetAceQLLocalFolder());

            AceQLTransaction transaction = await connection.BeginTransactionAsync();

            await transaction.CommitAsync();

            transaction.Dispose();

            string sql = "delete from customer_2";

            AceQLCommand command = new AceQLCommand
            {
                CommandText = sql,
                Connection  = connection
            };

            command.Prepare();

            await command.ExecuteNonQueryAsync();

            for (int i = 0; i < 3; i++)
            {
                sql =
                    "insert into customer_2 values (@parm1, @parm2, @parm3, @parm4, @parm5, @parm6, @parm7, @parm8, @parm9, @parm_10)";

                command = new AceQLCommand(sql, connection);

                int customer_id = i;

                command.Parameters.AddWithValue("@parm1", customer_id);
                command.Parameters.AddWithValue("@parm2", "Sir");
                command.Parameters.AddWithValue("@parm3", "André_" + customer_id);
                command.Parameters.Add(new AceQLParameter("@parm4", "Name_" + customer_id));
                command.Parameters.AddWithValue("@parm5", customer_id + ", road 66");
                command.Parameters.AddWithValue("@parm6", "Town_" + customer_id);
                command.Parameters.AddWithValue("@parm7", customer_id + "1111");
                command.Parameters.Add(new AceQLParameter("@parm8", AceQLNullType.VARCHAR)); //null value for NULL SQL insert.
                command.Parameters.AddWithValue("@parm9", customer_id + "_row_2");
                command.Parameters.AddWithValue("@parm_10", customer_id + "_row_count");

                CancellationTokenSource cancellationTokenSource = new CancellationTokenSource();
                await command.ExecuteNonQueryAsync(cancellationTokenSource.Token);
            }

            command.Dispose();

            sql     = "select * from customer_2";
            command = new AceQLCommand(sql, connection);

            // Our dataReader must be disposed to delete underlying downloaded files
            using (AceQLDataReader dataReader = await command.ExecuteReaderAsync())
            {
                while (dataReader.Read())
                {
                    AceQLConsole.WriteLine();
                    int i = 0;
                    AceQLConsole.WriteLine("GetValue: " + dataReader.GetValue(i++) + "\n"
                                           + "GetValue: " + dataReader.GetValue(i++) + "\n"
                                           + "GetValue: " + dataReader.GetValue(i++) + "\n"
                                           + "GetValue: " + dataReader.GetValue(i++) + "\n"
                                           + "GetValue: " + dataReader.GetValue(i++) + "\n"
                                           + "GetValue: " + dataReader.GetValue(i++) + "\n"
                                           + "GetValue: " + dataReader.GetValue(i++) + "\n"
                                           + "GetValue: " + dataReader.GetValue(i++) + "\n"
                                           + "GetValue: " + dataReader.GetValue(i++) + "\n"
                                           + "GetValue: " + dataReader.GetValue(i));
                }
            }

            AceQLConsole.WriteLine("Done.");
        }
Exemple #6
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        /// <summary>
        /// Executes our example using an <see cref="AceQLConnection"/>
        /// </summary>
        /// <param name="connection"></param>
        private static async Task ExecuteExample(AceQLConnection connection)
        {
            await connection.OpenAsync();

            AceQLConsole.WriteLine("host: " + connection.ConnectionInfo.ConnectionString);
            AceQLConsole.WriteLine("aceQLConnection.GetClientVersion(): " + AceQLConnection.GetClientVersion());
            AceQLConsole.WriteLine("aceQLConnection.GetServerVersion(): " + await connection.GetServerVersionAsync());
            AceQLConsole.WriteLine("AceQL local folder                : " + AceQLConnection.GetAceQLLocalFolder());

            RemoteDatabaseMetaData remoteDatabaseMetaData = connection.GetRemoteDatabaseMetaData();

            string userPath       = Environment.GetFolderPath(Environment.SpecialFolder.UserProfile);
            string schemaFilePath = userPath + "\\db_schema.out.html";

            // Download Schema in HTML format:
            using (Stream stream = await remoteDatabaseMetaData.DbSchemaDownloadAsync())
            {
                using (var fileStream = File.Create(schemaFilePath))
                {
                    stream.CopyTo(fileStream);
                }
            }

            bool displaySchema = false;

            if (displaySchema)
            {
                FileInfo fileInfo = new FileInfo(schemaFilePath);
                if (fileInfo.Exists)
                {
                    System.Diagnostics.Process.Start(schemaFilePath);
                }
            }

            AceQLConsole.WriteLine("Creating schema done.");

            JdbcDatabaseMetaData jdbcDatabaseMetaData = await remoteDatabaseMetaData.GetJdbcDatabaseMetaDataAsync().ConfigureAwait(true);

            AceQLConsole.WriteLine("Major Version: " + jdbcDatabaseMetaData.GetJDBCMajorVersion);
            AceQLConsole.WriteLine("Minor Version: " + jdbcDatabaseMetaData.GetJDBCMinorVersion);
            AceQLConsole.WriteLine("IsReadOnly   : " + jdbcDatabaseMetaData.IsReadOnly);

            AceQLConsole.WriteLine("JdbcDatabaseMetaData: " + jdbcDatabaseMetaData.ToString().Substring(1, 200));
            AceQLConsole.WriteLine();

            AceQLConsole.WriteLine("Get the table names:");
            List <String> tableNames = await remoteDatabaseMetaData.GetTableNamesAsync();

            AceQLConsole.WriteLine("Print the column details of each table:");
            foreach (String tableName in tableNames)
            {
                Table table = await remoteDatabaseMetaData.GetTableAsync(tableName);

                AceQLConsole.WriteLine("Columns:");
                foreach (Column column in table.Columns)
                {
                    AceQLConsole.WriteLine(column.ToString());
                }
            }

            AceQLConsole.WriteLine();

            String name          = "orderlog";
            Table  tableOrderlog = await remoteDatabaseMetaData.GetTableAsync(name);

            AceQLConsole.WriteLine("table name: " + tableOrderlog.TableName);
            AceQLConsole.WriteLine("table keys: ");
            List <PrimaryKey> primakeys = tableOrderlog.PrimaryKeys;

            foreach (PrimaryKey primaryKey in primakeys)
            {
                AceQLConsole.WriteLine("==> primaryKey: " + primaryKey);
            }
            AceQLConsole.WriteLine();

            AceQLConsole.WriteLine("Full table: " + tableOrderlog);

            AceQLConsole.WriteLine();
            AceQLConsole.WriteLine("Done.");
        }
Exemple #7
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        /// <summary>
        /// Executes our example using an <see cref="AceQLConnection"/>
        /// </summary>
        /// <param name="connection"></param>
        private static async Task ExecuteExample(AceQLConnection connection)
        {
            string IN_DIRECTORY  = AceQLConnection.GetAceQLLocalFolder() + "\\";
            string OUT_DIRECTORY = IN_DIRECTORY + "out\\";

            _ = Directory.CreateDirectory(OUT_DIRECTORY);

            await connection.OpenAsync();

            AceQLConsole.WriteLine("ConnectionString: " + connection.ConnectionInfo.ConnectionString);
            AceQLConsole.WriteLine();
            AceQLConsole.WriteLine("AceQLConnection.GetClientVersion(): " + AceQLConnection.GetClientVersion());
            AceQLConsole.WriteLine("AceQLConnection.GetServerVersion(): " + await connection.GetServerVersionAsync());
            AceQLConsole.WriteLine("AceQL local folder: ");
            AceQLConsole.WriteLine(AceQLConnection.GetAceQLLocalFolder());

            if (!CONSOLE_INPUT_DONE)
            {
                AceQLConsole.WriteLine();
                AceQLConsole.WriteLine("Press enter to close....");
                Console.ReadLine();
                CONSOLE_INPUT_DONE = true;
            }

            AceQLTransaction transaction = await connection.BeginTransactionAsync();

            await transaction.CommitAsync();

            transaction.Dispose();

            string sql = "delete from customer";

            AceQLCommand command = null;

            command = new AceQLCommand()
            {
                CommandText = sql,
                Connection  = connection
            };
            command.Prepare();

            await command.ExecuteNonQueryAsync();

            sql = "delete from dustomer";

            command = new AceQLCommand()
            {
                CommandText = sql,
                Connection  = connection
            };
            command.Prepare();

            try
            {
                await command.ExecuteNonQueryAsync();
            }
            catch (Exception exception)
            {
                AceQLConsole.WriteLine(exception.ToString());
            }

            sql     = "delete from dustomer where customer_id = @parm1 or fname = @parm2  ";
            command = new AceQLCommand()
            {
                CommandText = sql,
                Connection  = connection
            };
            command.Parameters.AddWithValue("@parm1", 1);
            command.Parameters.AddWithValue("@parm2", "Doe");

            try
            {
                await command.ExecuteNonQueryAsync();
            }
            catch (Exception exception)
            {
                AceQLConsole.WriteLine(exception.ToString());
            }



            for (int i = 0; i < 3; i++)
            {
                sql =
                    "insert into customer values (@parm1, @parm2, @parm3, @parm4, @parm5, @parm6, @parm7, @parm8)";

                command = new AceQLCommand(sql, connection);

                int customer_id = i;

                command.Parameters.AddWithValue("@parm1", customer_id);
                command.Parameters.AddWithValue("@parm2", "Sir");
                command.Parameters.AddWithValue("@parm3", "André_" + customer_id);
                command.Parameters.Add(new AceQLParameter("@parm4", "Name_" + customer_id));
                command.Parameters.AddWithValue("@parm5", customer_id + ", road 66");
                command.Parameters.AddWithValue("@parm6", "Town_" + customer_id);
                command.Parameters.AddWithValue("@parm7", customer_id + "1111");
                command.Parameters.Add(new AceQLParameter("@parm8", new AceQLNullValue(AceQLNullType.VARCHAR))); //null value for NULL SQL insert.

                CancellationTokenSource cancellationTokenSource = new CancellationTokenSource();
                await command.ExecuteNonQueryAsync(cancellationTokenSource.Token);
            }

            command.Dispose();

            sql     = "select * from customer";
            command = new AceQLCommand(sql, connection);

            // Our dataReader must be disposed to delete underlying downloaded files
            using (AceQLDataReader dataReader = await command.ExecuteReaderAsync())
            {
                //await dataReader.ReadAsync(new CancellationTokenSource().Token)
                while (dataReader.Read())
                {
                    AceQLConsole.WriteLine();
                    int i = 0;
                    AceQLConsole.WriteLine("GetValue: " + dataReader.GetValue(i++) + "\n"
                                           + "GetValue: " + dataReader.GetValue(i++) + "\n"
                                           + "GetValue: " + dataReader.GetValue(i++) + "\n"
                                           + "GetValue: " + dataReader.GetValue(i++) + "\n"
                                           + "GetValue: " + dataReader.GetValue(i++) + "\n"
                                           + "GetValue: " + dataReader.GetValue(i++) + "\n"
                                           + "GetValue: " + dataReader.GetValue(i++) + "\n"
                                           + "GetValue: " + dataReader.GetValue(i++));
                }
            }

            AceQLConsole.WriteLine("Before delete from orderlog 2");

            // Do next delete in a transaction because of BLOB
            transaction = await connection.BeginTransactionAsync();

            sql     = "delete from orderlog";
            command = new AceQLCommand(sql, connection);
            await command.ExecuteNonQueryAsync();

            command.Dispose();

            AceQLConsole.WriteLine("After delete from orderlog 2");

            await transaction.CommitAsync();

            Boolean doBlob = true;

            if (!doBlob)
            {
                return;
            }

            // Do next inserts in a transaction because of BLOB
            transaction = await connection.BeginTransactionAsync();

            try
            {
                for (int j = 1; j < 4; j++)
                {
                    sql =
                        "insert into orderlog values (@parm1, @parm2, @parm3, @parm4, @parm5, @parm6, @parm7, @parm8, @parm9)";

                    command = new AceQLCommand(sql, connection);

                    int customer_id = j;

                    string blobPath = null;

                    int index = getIndexFromDatabase();
                    blobPath = IN_DIRECTORY + "username_koala_" + index + ".jpg";

                    Stream stream = new FileStream(blobPath, FileMode.Open, System.IO.FileAccess.Read);

                    //customer_id integer NOT NULL,
                    //item_id integer NOT NULL,
                    //description character varying(64) NOT NULL,
                    //cost_price numeric,
                    //date_placed date NOT NULL,
                    //date_shipped timestamp without time zone,
                    //jpeg_image oid,
                    //is_delivered numeric,
                    //quantity integer NOT NULL,

                    command.Parameters.AddWithValue("@parm1", customer_id);
                    command.Parameters.AddWithValue("@parm2", customer_id);
                    command.Parameters.AddWithValue("@parm3", "Description_" + customer_id);
                    command.Parameters.Add(new AceQLParameter("@parm4", new AceQLNullValue(AceQLNullType.DECIMAL))); //null value for NULL SQL insert.
                    command.Parameters.AddWithValue("@parm5", DateTime.Now);
                    command.Parameters.AddWithValue("@parm6", DateTime.Now);
                    // Adds the Blob. (Stream will be closed by AceQLCommand)

                    command.Parameters.AddWithValue("@parm7", stream);

                    command.Parameters.AddWithValue("@parm8", 1);
                    command.Parameters.AddWithValue("@parm9", j * 2000);

                    AceQLConsole.WriteLine("Before await command.ExecuteNonQueryAsync()");
                    await command.ExecuteNonQueryAsync();

                    AceQLConsole.WriteLine("After await command.ExecuteNonQueryAsync()");
                }

                AceQLConsole.WriteLine("transaction.CommitAsync()");
                await transaction.CommitAsync();
            }
            catch (Exception)
            {
                await transaction.RollbackAsync();

                throw;
            }

            AceQLConsole.WriteLine("Before select *  from orderlog");

            // Do next selects in a transaction because of BLOB
            transaction = await connection.BeginTransactionAsync();

            sql     = "select * from orderlog";
            command = new AceQLCommand(sql, connection);

            using (AceQLDataReader dataReader = await command.ExecuteReaderAsync())
            {
                int k = 0;
                while (dataReader.Read())
                {
                    AceQLConsole.WriteLine();
                    int i = 0;
                    AceQLConsole.WriteLine("Get values using ordinal values:");
                    AceQLConsole.WriteLine("GetValue: " + dataReader.GetValue(i++) + "\n"
                                           + "GetValue: " + dataReader.GetValue(i++) + "\n"
                                           + "GetValue: " + dataReader.GetValue(i++) + "\n"
                                           + "GetValue: " + dataReader.GetValue(i++) + "\n"
                                           + "GetValue: " + dataReader.GetValue(i++) + "\n"
                                           + "GetValue: " + dataReader.GetValue(i++) + "\n"
                                           + "GetValue: " + dataReader.GetValue(i++) + "\n"
                                           + "GetValue: " + dataReader.GetValue(i++) + "\n"
                                           + "GetValue: " + dataReader.GetValue(i++));

                    //customer_id
                    //item_id
                    //description
                    //item_cost
                    //date_placed
                    //date_shipped
                    //jpeg_image
                    //is_delivered
                    //quantity

                    AceQLConsole.WriteLine();
                    AceQLConsole.WriteLine("Get values using column name values:");
                    AceQLConsole.WriteLine("GetValue: " + dataReader.GetValue(dataReader.GetOrdinal("customer_id"))
                                           + "\n"
                                           + "GetValue: " + dataReader.GetValue(dataReader.GetOrdinal("item_id")) + "\n"
                                           + "GetValue: " + dataReader.GetValue(dataReader.GetOrdinal("description")) + "\n"
                                           + "GetValue: " + dataReader.GetValue(dataReader.GetOrdinal("item_cost")) + "\n"
                                           + "GetValue: " + dataReader.GetValue(dataReader.GetOrdinal("date_placed")) + "\n"
                                           + "GetValue: " + dataReader.GetValue(dataReader.GetOrdinal("date_shipped")) + "\n"
                                           + "GetValue: " + dataReader.GetValue(dataReader.GetOrdinal("jpeg_image")) + "\n"
                                           + "GetValue: " + dataReader.GetValue(dataReader.GetOrdinal("is_delivered")) + "\n"
                                           + "GetValue: " + dataReader.GetValue(dataReader.GetOrdinal("quantity")));

                    AceQLConsole.WriteLine("==> dataReader.IsDBNull(3): " + dataReader.IsDBNull(3));
                    AceQLConsole.WriteLine("==> dataReader.IsDBNull(4): " + dataReader.IsDBNull(4));

                    // Download Blobs
                    int    index    = getIndexFromDatabase();
                    string blobPath = OUT_DIRECTORY + "username_koala_" + index + "_" + k + ".jpg";
                    k++;

                    using (Stream stream = await dataReader.GetStreamAsync(6))
                    {
                        using (var fileStream = File.Create(blobPath))
                        {
                            stream.CopyTo(fileStream);
                        }
                    }
                }
            }

            await transaction.CommitAsync();
        }
        /// <summary>
        /// Executes our example using an <see cref="AceQLConnection"/>
        /// </summary>
        /// <param name="connection"></param>
        private static async Task ExecuteExample(AceQLConnection connection)
        {
            //Environment.GetFolderPath(Environment.SpecialFolder.UserProfile);
            string IN_DIRECTORY  = "c:\\test\\";
            string OUT_DIRECTORY = "c:\\test\\out\\";

            await connection.OpenAsync();

            AceQLConsole.WriteLine("AceQLConnection.GetClientVersion(): " + AceQLConnection.GetClientVersion());
            AceQLConsole.WriteLine("AceQLConnection.GetServerVersion(): " + await connection.GetServerVersionAsync());
            AceQLConsole.WriteLine("AceQL local folder: ");
            AceQLConsole.WriteLine(AceQLConnection.GetAceQLLocalFolder());

            AceQLTransaction transaction = await connection.BeginTransactionAsync();

            await transaction.CommitAsync();

            transaction.Dispose();

            AceQLConsole.WriteLine("Before delete from orderlog");

            // Do next delete in a transaction because of BLOB
            transaction = await connection.BeginTransactionAsync();

            string       sql     = "delete from orderlog";
            AceQLCommand command = new AceQLCommand(sql, connection);
            await command.ExecuteNonQueryAsync();

            command.Dispose();

            await transaction.CommitAsync();

            // Do next inserts in a transaction because of BLOB
            transaction = await connection.BeginTransactionAsync();

            AceQLConsole.WriteLine("Before insert into orderlog");
            try
            {
                sql =
                    "insert into orderlog values (@parm1, @parm2, @parm3, @parm4, @parm5, @parm6, @parm7, @parm8, @parm9)";

                command = new AceQLCommand(sql, connection);

                int customer_id = 1;

                string blobPath = IN_DIRECTORY + "username_koala.jpg";
                Stream stream   = new FileStream(blobPath, FileMode.Open, System.IO.FileAccess.Read);

                //customer_id integer NOT NULL,
                //item_id integer NOT NULL,
                //description character varying(64) NOT NULL,
                //cost_price numeric,
                //date_placed date NOT NULL,
                //date_shipped timestamp without time zone,
                //jpeg_image oid,
                //is_delivered numeric,
                //quantity integer NOT NULL,

                command.Parameters.AddWithValue("@parm1", customer_id);
                command.Parameters.AddWithValue("@parm2", customer_id);
                command.Parameters.AddWithValue("@parm3", "Description_" + customer_id);

                command.Parameters.Add(new AceQLParameter("@parm4", new AceQLNullValue(AceQLNullType.DECIMAL))); //null value for NULL SQL insert.

                command.Parameters.AddWithValue("@parm5", DateTime.Now);
                command.Parameters.AddWithValue("@parm6", DateTime.Now);
                // Adds the Blob. (Stream will be closed by AceQLCommand)
                command.Parameters.AddWithValue("@parm7", stream);
                command.Parameters.AddWithValue("@parm8", 1);
                command.Parameters.AddWithValue("@parm9", 1 * 2000);

                await command.ExecuteNonQueryAsync();

                await transaction.CommitAsync();
            }
            catch (Exception)
            {
                await transaction.RollbackAsync();

                throw;
            }

            AceQLConsole.WriteLine("Before select *  from orderlog");

            // Do next selects in a transaction because of BLOB
            transaction = await connection.BeginTransactionAsync();

            sql     = "select * from orderlog where cutomer_id = 1 and order_id = 1";
            command = new AceQLCommand(sql, connection);

            using (AceQLDataReader dataReader = await command.ExecuteReaderAsync())
            {
                int k = 0;
                while (dataReader.Read())
                {
                    AceQLConsole.WriteLine();
                    int i = 0;
                    AceQLConsole.WriteLine("GetValue: " + dataReader.GetValue(i++) + "\n"
                                           + "GetValue: " + dataReader.GetValue(i++) + "\n"
                                           + "GetValue: " + dataReader.GetValue(i++) + "\n"
                                           + "GetValue: " + dataReader.GetValue(i++) + "\n"
                                           + "GetValue: " + dataReader.GetValue(i++) + "\n"
                                           + "GetValue: " + dataReader.GetValue(i++) + "\n"
                                           + "GetValue: " + dataReader.GetValue(i++) + "\n"
                                           + "GetValue: " + dataReader.GetValue(i++) + "\n"
                                           + "GetValue: " + dataReader.GetValue(i++));

                    // Download Blobs
                    string blobPath = OUT_DIRECTORY + "username_koala_" + k + ".jpg";
                    k++;

                    using (Stream stream = await dataReader.GetStreamAsync(6))
                    {
                        using (var fileStream = File.Create(blobPath))
                        {
                            //stream.CopyTo(fileStream);
                            CopyStream(stream, fileStream);
                        }
                    }
                }
            }

            await transaction.CommitAsync();
        }