In this article Barry Mavin, CEO and Chief Software Architect for Recital provides details on how to use the Recital Universal .NET Data Provider with the Recital Database Server.

Overview

A data provider in the .NET Framework serves as a bridge between an application and a data source. A data provider is used to retrieve data from a data source and to reconcile changes to that data back to the data source.

Each .NET Framework data provider has a DataAdapter object: the .NET Framework Data Provider for OLE DB is the OleDbDataAdapter object, the .NET Framework Data Provider for SQL Server is the SqlDataAdapter object, the .NET Framework Data Provider for ODBC is the OdbcDataAdapter object, and the .NET Framework Data Provider for the Recital Database Server is the RecitalDataAdapter object.

The Recital Universal .NET Data Provider can access any data sources supported by the Recital Database Server. It is not restricted to only access Recital data. It can be used to access server-side ODBC, JDBC and OLE DB data sources also.

Core classes of the Data Provider

The Connection, Command, DataReader, and DataAdapter objects represent the core elements of the .NET Framework data provider model. The Recital Universal .NET Data Provider is plug compatible with the .NET Framework Data Provider for SQL Server. All SQL Server classes are prefixed with "Sql" e.g. SqlDataAdaptor. To use the Recital Universal Data Adaptor, simply change the "Sql" prefix to "Recital" e.g. RecitalDataAdaptor.

The following table describes these objects.

Along with the core classes listed in the preceding table, a .NET Framework data provider also contains the classes listed in the following table.

The Recital Universal .NET Data Provider provides connectivity to the Recital Database Server running on any supported platform (Windows, Linux, Unix, OpenVMS) using the RecitalConnection object. The Recital Universal .NET Data Provider supports a connection string format that is similar to the SQL Server connection string format.

The basic format of a connection string consists of a series of keyword/value pairs separated by semicolons. The equal sign (=) connects each keyword and its value.

The following table lists the valid names for keyword values within the ConnectionString property of the RecitalConnection class.

Populating a DataSet from a DataAdaptor

The ADO.NET DataSet is a memory-resident representation of data that provides a consistent relational programming model independent of the data source. The DataSet represents a complete set of data including tables, constraints, and relationships among the tables. Because the DataSet is independent of the data source, a DataSet can include data local to the application, as well as data from multiple data sources. Interaction with existing data sources is controlled through the DataAdapter.

A DataAdapter is used to retrieve data from a data source and populate tables within a DataSet. The DataAdapter also resolves changes made to the DataSet back to the data source. The DataAdapter uses the Connection object of the .NET Framework data provider to connect to a data source and Command objects to retrieve data from and resolve changes to the data source.

The SelectCommand property of the DataAdapter is a Command object that retrieves data from the data source. The InsertCommand, UpdateCommand, and DeleteCommand properties of the DataAdapter are Command objects that manage updates to the data in the data source according to modifications made to the data in the DataSet.

The Fill method of the DataAdapter is used to populate a DataSet with the results of the SelectCommand of the DataAdapter. Fill takes as its arguments a DataSet to be populated, and a DataTable object, or the name of the DataTable to be filled with the rows returned from the SelectCommand.

The Fill method uses the DataReader object implicitly to return the column names and types used to create the tables in the DataSet, as well as the data to populate the rows of the tables in the DataSet. Tables and columns are only created if they do not already exist; otherwise Fill uses the existing DataSet schema.

Examples in C#:

////////////////////////////////////////////////////////////////////////
// include the references below
using System.Data;
using Recital.Data;

////////////////////////////////////////////////////////////////////////
// The following code example creates an instance of a DataAdapter that 
// uses a Connection to the Recital Database Server Southwind database 
// and populates a DataTable in a DataSet with the list of customers. 
// The SQL statement and Connection arguments passed to the DataAdapter 
// constructor are used to create the SelectCommand property of the DataAdapter.
public DataSet SelectCustomers()
{
	RecitalConnection swindConn = new
		RecitalConnection("Data Source=localhost;Initial Catalog=southwind");
	RecitalCommand selectCMD = new
		RecitalCommand("SELECT CustomerID, CompanyName FROM Customers", swindConn);
	selectCMD.CommandTimeout = 30;
	RecitalDataAdapter custDA = new RecitalDataAdapter();
	custDA.SelectCommand = selectCMD;
	swindConn.Open();
	DataSet custDS = new DataSet();
	custDA.Fill(custDS, "Customers");
	swindConn.Close();
	return custDS;
}

////////////////////////////////////////////////////////////////////////
// The following example uses the RecitalCommand, RecitalDataAdapter and 
// RecitalConnection, to select records from a database, and populate a 
// DataSet with the selected rows. The filled DataSet is then returned. 
// To accomplish this, the method is passed an initialized DataSet, a 
// connection string, and a query string that is a SQL SELECT statement
public DataSet SelectRecitalRows(DataSet dataset, string connection, string query) 
{
	RecitalConnection conn = new RecitalConnection(connection);
	SqlDataAdapter adapter = new RecitalDataAdapter();
	adapter.SelectCommand = new RecitalCommand(query, conn);
	adapter.Fill(dataset);
	return dataset;
}

$hdiutil create /tmp/tmp.dmg -ov -volname "RecitalInstall" -fs HFS+ -srcfolder "/tmp/macosxdist/" 

$hdiutil convert /tmp/tmp.dmg -format UDZO -o RecitalInstall.dmg

In this article Barry Mavin, CEO and Chief Software Architect for Recital provides details on how the Recital Database Server can be used to provide a solution for Universal Data Integration.

Overview

The Recital Database Server handles universal cross-platform data access to a wide range of data sources. The database server natively handles full remote SQL data access to Recital, Visual FoxPro, FoxPro, FoxBASE, Clipper and older dBase data. Using Bridges, it handles full remote SQL data access to C-ISAM and OpenVMS RMS. Using gateway connections, it handles full remote SQL data access to Oracle, MySQL, PostgreSQL, SQL Server, server-side ODBC, server-side JDBC and server-side OLE DB data sources. With its ability to access data using server-side ODBC, JDBC and OLE DB drivers from clients on all supported operating systems (Windows, Linux, Unix, OpenVMS), the Recital Database Server is an ideal Data Integration Solution for applications of all sizes and complexity.

Universal Data Integration Solutions

There are several ways in which data may be accessed by the Database Server.

Table 1:

Client Universal Data Access solutions for accessing local or remote data.

Table 2:

Windows Server Universal Data Access solutions accessible from any remote client running on Windows, Linux, Unix or OpenVMS:

Table 3:

Linux and Unix Server Universal Data Access solutions accessible from any remote client running on Windows, Linux, Unix or OpenVMS:

Table 4:

OpenVMS Server Universal Data Access solutions accessible from any remote client running on Windows, Linux, Unix or OpenVMS:

Supported Data Sources

Native Data Access

The Recital Database Server has native built-in support for the following data sources:

• Recital
• Visual FoxPro
• FoxPro
• FoxBASE
• Clipper
• dBase

You can setup tables to work with using the Database Administration Tool in Recital Enterprise Studio.

Bridges

Using Bridges, you can access the following data sources as if they were standard Recital/FoxPro tables:

• CISAM
• OpenVMS RMS

You can setup bridges using the Database Administration Tool in Recital Enterprise Studio.

Gateways/Connections

Using Gateways, you can transparently access the following local or remote data sources:

• Recital
• Oracle
• ODBC (Server-side ODBC data sources)
• JDBC (Server-side JDBC data sources)
• OLEDB Use this to connect to SQL Server and other Windows OLE DB data sources)
• MySQL
• PostgreSQL

Remote Data Object functions

Recital 10 includes a complete and robust set of data source independent functions for accession MySQL, Oracle, DB2 and Postgres. This article explains how to use them.

Client Data Access drivers

Included with the Recital Database Server are three Client drivers. These Client drivers can access any data sources supported by the Recital Database Server. They are not restricted to accessing only Recital data. They can be used to access server-side ODBC, JDBC and OLE DB data sources also.

Recital Universal .NET Data Provider

Use this client driver when building .NET applications with Visual Studio .NET. A data provider in the .NET Framework serves as a bridge between an application and a data source. A data provider is used to retrieve data from a data source and to reconcile changes to that data back to the data source.

Key features of the Recital Universal .NET Data Provider:

• Fully Internet enabled
  The Recital Universal .NET Data Provider works across the internet providing access to a wide range of data sources located on remote servers running Windows, Linux, Unix and OpenVMS.
• SQL Server compatible
  The Recital Universal .NET Data Provider is plug compatible with the .NET Framework SQL Server Data Provider.
• Cross-platform Data Integration
  Using the Recital Universal .NET Data Provider, you can connect to remote Windows, Linux, Unix or OpenVMS servers and access any data source supported by the Recital Database Server.
• Managed code
  The Recital Universal .NET Data Adaptor written in C# is 100% .NET Framework managed code.
• Runs on Windows Mobile
  The Recital Universal .NET Data Adaptor runs under the .NET Compact Framework on Windows Mobile.

Recital Universal JDBC Driver

The JDBC API is the industry standard for database-independent connectivity between the Java programming language and a wide range of databases. The JDBC API provides a call-level API for SQL-based database access. JDBC technology allows you to use the Java programming language to exploit "Write Once, Run Anywhere" capabilities for applications that require access to enterprise data.

Key features of the Recital Universal JDBC Driver:

• Fully Internet enabled
  The Recital Universal JDBC driver works across the internet providing access to a wide range of data sources located on remote servers running Windows, Linux, Unix and OpenVMS.
• JDBC 3.0 API
  The Recital Universal JDBC driver supports the JDBC 3.0 API.
• Pure Java Type 3 Driver
  The Recital Universal JDBC driver is a 100% pure Java Type 3 driver.
• Full Access to Metadata
  The JDBC API provides metadata access that enables the development of sophisticated applications that need to understand the underlying facilities and capabilities of a specific database connection.
• Cross-platform Data Integration
  Using the Recital Universal JDBC driver, you can connect to remote Windows, Linux, Unix or OpenVMS servers and access any data source supported by the Recital Database Server.
• No Installation
  A pure JDBC technology-based driver does not require special installation; it is automatically downloaded as part of the applet that makes the JDBC calls. The Recital Universal JDBC Driver is 100% java.

Recital Universal ODBC Driver

Connect to remote data from Microsoft Office or other applications that support ODBC data access. The Recital Universal ODBC Driver is also available for Linux and Unix.

Key features of the Recital Universal ODBC Driver:

• Fully Internet enabled
  The Recital Universal ODBC driver works across the internet providing access to a wide range of data sources located on remote servers running Windows, Linux, Unix and OpenVMS.
• Works with Crystal Reports
  The Recital Universal ODBC driver supports the SQL syntax generated by Crystal Reports.
• Works with Microsoft Office
  The Recital Universal ODBC driver works with Microsoft Office products.
• Works with PHP on Linux
  The Recital Universal ODBC driver is available for Linux and works with PHP.