Question

So, there’s a field in the db in which I store serialized arrays.

$array = array('count1' => 10, 'count2' => 20, 'count3' => 4);

serialized:

a:3:{s:6:"count1";i:10;s:6:"count2";i:20;s:6:"count3";i:4;}

Would it be possible to pull count1+count2+count3 using a mysql query? I guess I’m looking for something like php’s explode. Pretty sure this can’t be done, but I thought I’d ask.

I need to pull the highest count1+count2+count3 rows and return the total count. Looping through each row and unserializing wouldn’t work since there are TONS of rows.

Answer 1

If you need to access parts of your serialized data via SQL, you need to store them in separate columns.

While it might be possible to use techniques such as regular expressions to access those three values in this string, it would be extremely slow when used in a WHERE criterion as indexes would be useless – not to mention that it would be a huge mess, way worse than using goto in a programming language.

So the solution is to create a new columns and then iterate over all rows, unserialize them, and store the sum into the new column. That might take a while but you’ll only need to it once.

Depending on your application it might be better to create three columns and store each value separately.