Creating a PostgreSQL and MySQL driver
By Tony Marston2005-09-20
Conclusion
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In theory it should be a relatively simple exercise to switch from one SQL database to another. As is usual in this universe there is a big difference between theory and practice. Although all the database vendors 'supposedly' follow the same standards, they all seem to have followed different interpretations of those standards, followed by different implementations, all of which are capped off with different proprietary extensions. This makes the developer's job of switching database vendors more complicated than it need be, but by following some simple steps it is possible to take that mountain and turn it back into a mole hill:
- When it comes to database capabilities it is better to stick to the lowest common denominator and avoid those custom extensions which are unique to a particular vendor's database. Some people say that if you are paying money for a database with fancy extensions then it is a waste of money not to use them. But by locking yourself into a particular vendor's product you may actually be th owing money down the drain as you are effectively making it impossible to switch to a cheaper database from a different vendor.
- By having all the database access code isolated in a single component, a database driver, instead of having it spread throughout the system means that you only have to change that one component instead of the whole system. Although the internals of each database driver are totally unique they all share the same API's, therefore the remainder of the system is totally unaffected when one driver is swapped for another.
I have included a version of my PostgreSQL driver with my sample application, so you now have the option of running it with either MySQL or PostgreSQL.
NOTE: All testing was done against PostgreSQL version 8.0.3 running on Windows XP using PHP versions 4.3.11 and 5.0.4.
Tutorial Pages:
» Introduction
» Administrative programs
» Connecting to a Database
» CREATE TABLE syntax
» SQL queries
» Conclusion
