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 Before
ODBC
- Applications were written in that language
for that specific database.
- Each system (such as Oracle or IBM) had its
own programming language, so programmers either had to know both
languages or team up with the other programmers to coordinate
efforts.
- No other language can interact with that
database, and the language can communicate only with the databases
made by that manufacturer.
- A program couldn’t be adapted to handle
different databases, so it was clear there needed to be one generic
access method to databases.
ODBC
Overview
An application programming interface that enables
applications to access data from a variety of existing data sources
standard specification for cross-platform database access.
- ODBC allows a single uniform language to
access different databases.
- Previously, a programming language talked
directly to a database, but with ODBC, a programming language talks
to the API.
- The API is developed for each database, so
it knows what kind of database you’re trying to talk to (because
you told it)
- It interprets your requests so that the
database can return the information. Since every database driver has
to follow the same standard for the APIs, the programming code
doesn’t have to change for each database.
ODBC Drivers
- This open connectivity to a database now
allows an application to get data from any kind of database.
- The request from the client application is
passed to the ODBC Driver Manager on the client or server.
- The ODBC Driver Manager decides whether the
database driver is installed and passes the request to physical
database.
- The database on the server fulfills or
denies the request and passes the appropriate information back to
ODBC driver on the client.
- The ODBC driver interprets any error
information available on the client, if necessary.
- Finally, the ODBC driver returns the
information to the client application.
ODBC Control Panel
DSN (Data Source Name)
Where ODBC Fits In
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