So I've got this form with an array of checkboxes to search for an event. When you create an event, you choose one or more of the checkboxes and then the event gets created with these "attributes". What is the best way to store it in a MySQL database if I want to filter results when searching for these events? Would creating several columns with boolean values be the best way? Or possibly a new table with the checkbox values only?
I'm pretty sure selializing is out of the question because I wouldn't be able to query the selialized string for whether the checkbox was ticked or not, right?
Thanks
You can use the set datatype or a separate table that you join. Either will work.
I would not do a bunch of columns though.
You can search the set easily using FIND_IN_SET(), but it's not indexed, so it depends on how many rows you expect (up to a few thousand is probably OK - it's a very fast search).
The normal solution is a separate table with one column being the ID of the event, and the second column being the attribute using the enum datatype (don't use text, it's slower).
create separate columns or you can store them all in one column using bit mask
One way would be to create a new table with a column for each checkbox, as already described by others. I'll not add to that.
However, another way is to use a bitmask. You have just one column myCheckboxes and store the values as an int. Then in the code you have constants or another appropriate way to store the correlation between each checkbox and it's bit. I.e.:
CHECKBOX_ONE 1
CHECKBOX_TWO 2
CHECKBOX_THREE 4
CHECKBOX_FOUR 8
...
CHECKBOX_NINE 256
Remember to always use the next power of two for new values, otherwise you'll get values that overlap.
So, if the first two checkboxes have been checked you should have 3 as the value of myCheckboxes for that row. If you have ONE and FOUR checked you'd have 9 as the values of myCheckboxes, etc. When you want to see which rows have say checkboxes ONE, THREE and NINE checked your query would be like:
SELECT * FROM myTable where myCheckboxes & 1 AND myCheckboxes & 4 AND myCheckboxes & 256;
This query will return only rows having all this checkboxes marked as checked.
You should also use bitwise operations when storing and reading the data.
This is a very efficient way when it comes to speed. You have just a single column, probably just a smallint, and your searches are pretty fast. This can make a big difference if you have several different collections of checkboxes that you want to store and search trough. However, this makes the values harder to understand. If you see the value 261 in the DB it'll not be easy for a human to immeditely see that this means checkboxes ONE, THREE and NINE have been checked whereas it is much easier for a human seeing separate columns for each checkbox. This normally is not an issue, cause humans don't need to manually poke the database, but it's something worth mentioning.
From the coding perspective it's not much of a difference, but you'll have to be careful not to corrupt the values, cause it's not that hard to mess up a single int, it's magnitudes easier than screwing the data than when it's stored in different columns. So test carefully when adding new stuff. All that said, the speed and low memory benefits can be very big if you have a ton of different collections.