On Mon, Jan 21, 2002 at 09:43:09AM +0000, Dan Kolb wrote:
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On Monday 21 Jan 2002 09:35 am, Mark Evans wrote:
Chicken/Egg... Anyway isn't one of the meanings of SQL "Standard Query Language" :)
I thought it was Structured Query Language. But it should be pretty much the same whatever SQL database you use. However, opening a connection to a database isn't necessarily the same - you use different commands to open an PostgreSQL database compared to a MySQL database (at least I gather that from reading various Perl/PHP scripts)
With perl there is what's called a DBD/DBI (database dependent/database independent) interface to accessing SQL databases. You have one module (the DBD) that lies directly next to the database which implements the calls supported by the database & on top of that the more abstract DBI module through which you pass your SQL queries. This makes it easy to migrate your code from one database to another or write another DBI for some yet unsupported database. This is how these people should have designed their system so that it doesn't suck and customers can then use whatever SQL database they like with minimal coding effort required by the company. If they'd also then made the interface open then customers/db companies could even write the database dependent bit themselves. Different databases all implement the SQL'92 standard a bit differently (it's abstract in parts) which is why you can have these problems. I don't know if the standard has been updated lately or is likely to be. I don't know what the licensing terms for Oracle on Linux are but it could be worth looking into for an educational establishment. As I understand it, Oracle most completely implements the SQL standard & is meant to be a good (though expensive) bit of software. Of the free relational databases then postgresql supports more of the standard & implements important things like transactions (although MySQL might do these too now) then the others last time I looked. As for application software that's equivalent to this stuff you're looking into, I don't know off-hand. -- Frank *-*-*-*-*-*-*-*-*-*-* Boroughbridge. Tel: 01423 323019 --------- PGP keyID: 0xC0B341A3 *-*-*-*-*-*-*-*-*-*-* http://www.esperance-linux.co.uk/ Boob's Law: You always find something in the last place you look.