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Er mohit lib (talk | contribs) I have added the content related to different level of abstraction. which will give more clear idea of database abstraction. |
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{{Refimprove|date=September 2014}}
A '''database abstraction layer''' is an [[application programming interface]] which unifies the communication between a computer application and [[database]]s such as [[MSSQL|SQL Server]], [[IBM DB2|DB2]], [[MySQL]], [[PostgreSQL]], [[Oracle database|Oracle]] or [[SQLite]]. Traditionally, all database vendors provide their own interface tailored to their products, which leaves it to the application programmer to implement code for all database interfaces he or she would like to support. Database abstraction layers reduce the amount of work by providing a consistent API to the developer and hide the database specifics behind this interface as much as possible. There exist many abstraction layers with different interfaces in numerous programming languages. If an application has such a layer built in, it is called '''database-agnostic'''.<ref>http://searchdatamanagement.techtarget.com/definition/database-agnostic</ref>
== Database levels of Abstraction ==
=== Physical level(lowest level) ===
It defines how data is stored. It is very complex and used by developers.
=== Conceptual or logical level(Middle or next highest level) ===
It defines data in terms of a data model. It tells what data is stored and described in small numbers. This level is usually used by '''DBA''' (Database administrator)
=== External or view level ===
It defines a number of simplified ___domain-specific views. It describes only part of databases . This level is used by users.
<ref>http://www.dmst.aueb.gr/dds/etech/db/abstr.htm</ref>
== Database Abstraction in the API ==
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