Microsoft SQL Server Client Issues

Microsoft SQL Server is a powerful structured query language (SQL) database server that enables the development of robust and efficient, information-intensive applications.

Developers can write applications for SQL Server by programming with DB-Library for C, the C-language version of the communication library for SQL Server, or with DB-Library for Visual Basic, the Visual Basic version of the communication library for SQL Server.

DB-Library for C is an API that consists of C functions and macros that allow an application to interact with SQL Server. Included are functions that send Transact-SQL statements to SQL Server and functions that process the results of those statements. Other functions handle errors and convert data.

DB-Library for C offers a rich set of functions for:

• Opening connections.
• Formatting queries.
• Sending query batches to the server and retrieving the resulting data.
• Using scrollable cursors.
• Bulk-copying data from files or program variables to and from the server.
• Controlling two-phase commit operations between several participating SQL servers.
• Executing stored procedures or remote stored procedures.

In addition to DB-Library, SQL Server supports the Microsoft Open Database Connectivity (ODBC) call-level API. ODBC enables applications for Windows, Windows NT, and Windows 95 to access multiple data sources, including a wide range of relational databases and local indexed sequential access method (ISAM) data. In most cases, DB-Library and ODBC are equally capable of creating SQL Server client applications. ODBC enables applications to access more data sources, while DB-Library provides equivalent functionality in multiple-client environments, including the MS-DOS operating system specialized support for SQL Server (such as bulk copy and two-phase commit).

For more information about DB-Library and ODBC, see "Microsoft SQL Server Programmer's Toolkit" and "ODBC" in the "Database and Messaging Services" section of the Microsoft Platform SDK.

Using Embedded SQL allows programmers to place SQL statements into programs written in a standard programming language, which is termed the host language. The Embedded SQL approach, using programming statements similar to Transact-SQL, is more concise than the function-call approach and is tightly coupled to the existing database structure. Because the SQL statements are directly included in the source code, Embedded SQL programs are usually special-purpose applications. Embedded SQL is well suited for environments where the programmer is also in control of the database structure. However, it is less flexible for environments where the database structure is changing or is not known in advance.

For more information about Embedded SQL, see the Embedded SQL for C 4.22 SDK on the Microsoft Developer Network Development Library compact disc.