Database Connectivity...

SQL Server Protocols is the layer of network technologies that enables client applications to talk to the server:

• The SQL Server Network Interface (SNI) protocol unifies communications over TCP, Named Pipes, and Shared Memory.
• The Tabular Data Stream (TDS) protocol is an application layer protocol where packets are encapsulated in the packets built for the protocol stack.
• SQL Server Browser runs as a Windows service on the server. SQL Server Browser listens for incoming requests for SQL Server resources and provides information about SQL Server instances that are installed on the computer.

These SQL protocols and components are necessary to allow for communications with SQL Server by the clients.

ADO.NET is the core data access technology for .NET languages. Use the System.Data.SqlClient namespace to access SQL Server, or providers from other suppliers to access their stores. Use System.Data.Odbc or System.Data.Oledb to access data from .NET languages using other data access technologies. Use System.Data.Dataset when you need an offline data cache in client applications. It also provides local persistence and XML capabilities that can be useful in web services.

***Introducing ODBC Driver Connectivity for Linux***

ODBC is the primary native data access API for SQL Server and many other data sources. There is probably an ODBC driver for just about every data source you can think of. It is the primary data access API for applications written in C and C++. Other languages (including COBOL, Perl, PHP and Python) employ ODBC and it is widely used in data integration scenarios.

OLE DB uses COM to provide data access capabilities similar to ODBC. For most tasks, ODBC typically requires less code to achieve the same functionality and often provides better performance.

***Microsoft OLE DB Provider to be Deprecated***

In its continued commitment to interoperability, Microsoft provides a Java Database Connectivity (JDBC) driver for use with SQL Server. The Microsoft JDBC Driver for SQL Server is available to all SQL Server users at no additional charge, and provides access to various versions of SQL Server and SQL Azure from any Java application, application server, or Java-enabled applet. This driver is a Type 4 JDBC driver that provides database connectivity through the standard JDBC application program interfaces (APIs).

The SQL Server Driver for PHP is designed to enable reliable, scalable integration with SQL Server for PHP applications. The SQL Server Driver for PHP is a PHP 5 extension that allows the reading and writing of SQL Server data from within PHP scripts. It provides interfaces for accessing data in all Editions of SQL Server 2005 and later (including Express Editions) as well as SQL Azure, and makes use of PHP features, including PHP streams to read and write large objects.