Today, we take a look at what SQL is and describe its major features and benefits. This is chapter one of McGraw-Hill/Osborne's SQL: The Complete Reference (ISBN 0-07-222559-9, 2004) by James R. Groff and Paul N. Weinberg.
Introduction to SQL - SQL Features and Benefits (Page 4 of 8 )
SQL is both an easy-to-understand language and a comprehensive tool for managing data. Here are some of the major features of SQL and the market forces that have made it successful:
Portability across computer systems
IBM endorsement and commitment (DB2)
Microsoft commitment (SQL Server, ODBC, and ADO)
High-level, English-like structure
Interactive, ad hoc queries
Programmatic database access
Multiple views of data
Complete database language
Dynamic data definition
Enterprise application support
Extensibility and object technology
Internet database access
Java integration (JDBC)
These are the reasons why SQL has emerged as the standard tool for managing data on personal computers, minicomputers, and mainframes. They are described in the sections that follow.
SQL is offered by all of the leading DBMS vendors, and no new database product over the last decade has been highly successful without SQL support. A SQL-based database and the programs that use it can be moved from one DBMS to another vendorís DBMS with minimal conversion effort and little retraining of personnel. Database tools, such as query tools, report writers, and application generators, work with many different brands of SQL databases. The vendor independence thus provided by SQL was one of the most important reasons for its early popularity and remains an important feature today.
Portability Across Computer Systems
SQL-based database products run on computer systems ranging from mainframes and midrange systems to personal computers, workstations, a wide range of specialized server computers, and even handheld devices. They operate on stand-alone computer systems, in departmental local area networks, and in enterprisewide or Internetwide networks. SQL-based applications that begin on single-user or departmental server systems can be moved to larger server systems as they grow. Data from corporate SQL-based databases can be extracted and downloaded into departmental or personal databases. Finally, economical personal computers can be used to prototype a SQL-based database application before moving it to an expensive multiuser system.
An official standard for SQL was initially published by the American National Standards Institute (ANSI) and the International Standards Organization (ISO) in 1986, and was expanded in 1989 and again in 1992 and 1999. SQL is also a U.S. Federal Information Processing Standard (FIPS), making it a key requirement for large government computer contracts. Over the years, other international, government, and vendor groups have pioneered the standardization of new SQL capabilities, such as call-level interfaces or object-based extensions. Many of these new initiatives have been incorporated into the ANSI/ISO standard over time. The evolving standards serve as an official stamp of approval for SQL and have speeded its market acceptance.
Remember: this is chapter one of SQL: The Complete Reference, by Groff and Weinberg (McGraw-Hill/Osborne, ISBN 0-07-222559, 2004). You can find this and many other fine McGraw-Hill Osborne books at your favorite bookstores. Buy this book now.