Transferring Data 'Tween Databases
Sysbotz writes "A common request our company gets is how to get data from Access, Paradox, or some other database format and transfer it to a MySQL database. Well we have written a article on how to do this. W accomplish this task by writing a PHP script to read a database file through ODBC and then to construct a SQL file of the data that can then be read into MySQL. I think some slashdotters would like this."
The Perl DBI can talk to all of those listed databases and more. It'd be trivial to fetch everything from one database and store it in another, without worrying about local quoting conventions, as long as you use the DBI placeholders.
This is totally worthless.
Do mods just let anything with the words 'PHP' and/or 'MySQL' make it on the website?
The article is less than 2 screen pages long, it's not much more than a code dump, and it's totally hardcoded for a specific and individual database table.
It also only covers Windows installations of PHP and and person who knows that they need to move from one database to another, and what PHP is, is smart enough to do what this author wrote.
I don't diss the author on this, it looks as if he is just new to computers and doesn't know any better.
But geez, if this is the crap that we allow on slashdot now, I'm just gonna start submitting articles on 'How cool Google is'
You should check it out, it's open source.
Frankly, even the overhead of having to construct the INSERT sql string is waste. You also don't want to maintain the indexes in the target table for each row update. MySQL doesn't have transactions, so you don't have to worry about commit-frequency, but if your load stops in the middle somewhere, I'm not sure what you do.
Oracle provides a loader utility called sql*loader that eliminates the overhead of the per-row maintenance. It has a mode called "Direct Load" which can bypass trigger processing and directly write binary datablock output. This is the fastest way to load data. Of course bypassing triggers is of no interest to MySQL users because MySQL doesn't have triggers, but if it did you'd have another thing to worry about with loading data into MySQL.
As an alternate to sql*loader, you could use external tables or Oracle Generic Connectivity to create an oracle table whose data was supplied by a flat file or ODBC connection. Then you would typeor (faster)Both of which would blow away the proposed method speed-wise.