Another redesign. This time with BlogPower™. Not sure what will happen
about content. Probably will get content until I get bored, then wither.
It seems that I haven't been updating my website as often as I should. There's a lot of information that I want to share with people, but I haven't come up with a simple way of getting it all across.
In the mean time, there is a menu to the left there <--
The reason most people have web pages I do not know, however I do like to be able to find out about people by looking at their web pages. I am less interested to find out about their gerbil though. It is like Internet spying, but spying on what they want you to know. So that people can find a little about me I have written these pages.
My PGP/GPG key is available as this file
There is a more blog-style diary here
Why doesn't the update command in SQL support an "order by" clause?
Logically you'd think "That'll be because the order doesn't matter" - SQL is all mathematical set operations. Unfortunately it does.
Think of the case (that you shouldn't do), of altering the primary key of a table:
update my_table set id = id + 1;
Think of this as being like Hilbert's Hotel - if there were no collisions before running it (and nothing added to it whilst the update runs) then there should be no collisions afterwards.
Unfortunately you do get an error indicating a violation of the primary key uniqueness constraint. Obviously it sets the id of the row which used to have id=1 to be id=2 then checks for the constraint at this point there is already a row with id=2 (that we're intending to make id=3). If we updated them in order from the highest id first, then there wouldn't be any problem as we would free up a "room" before trying to put anyone else in it.
Last updated: 12:06, 25 Jun 2008 Link..