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A Mysql Question..... - El Forum - 06-11-2010
[eluser]mddd[/eluser]
@garymardell: the disadvantage of that, is that you cannot easily search the database for users who have a certain setting enabled.
@flyenig: That solution is not wrong, but as a said before, you need to change the database if you want to add a new setting to the system. If that's alright with you, your solution will be fine.
A Mysql Question..... - El Forum - 06-11-2010
[eluser]glopv2[/eluser]
Perhaps thinking about how the data will be accessed will help. I am guessing that 99% of all DB queries will be something like
Quote:"Does user X have Y notification enabled? Yes or No"I am guessing you'll never need to do a look-up like "Give me all the users who have Y notification enabled." That may guide you in setting up your table structure.
For instance, this might be an instance where you create a bit field variable, and simply store it as an unsigned integer*. The pro of this: saves lots of space**, doesn't have any impact on the "Does X have Y enabled" lookup speed. The con: loss of simplicity, harder for a human to read, you lose the ability to quickly ask "Who has Y enabled."
@mddd's version would make a lot of sense if you expect most people to keep the defaults. That way you only would store a much smaller "modifications" amount of data, rather than having a big ol' table of data that mostly repeats itself.
I hope this makes sense.
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* If the number is written in binary, e.g. 1101, then each "digit" of the binary number represents the yes/no of a certain field. so if you decide you have 4 notifications A, B, C, and D, and they map like A=>1000, B=>0100, C=>0010, D=>0001..... actually never mind just look on wikipedia. The point is you could query this integer/bit field out of the database and use bitwise operators to quickly determine the yes/no you're looking for.
** Saving the yes/no as an enum for each property will store each yes/no for each user as a byte. My way will use a bit. You should use 1/8 as much space.
A Mysql Question..... - El Forum - 06-11-2010
[eluser]flyenig[/eluser]
Thank you all for your replys, yea @mddd yours makes sence and thanks @glopv2 for making it more clear.
garymardell thanks for your suggestion 8)