Can you make comparisons between IF e IFNULL ?
I mean I want to compare an IFNULL statement with other IFNULLs and take the largest one out of them, but I do not know how to do it or if it can be done.
At the same time I have a question with the sentence GROUP BY I am using it to not show repeated results, but when using it (it happens to me with some items that I want to look for) the search takes even 4 minutes; I use EXPLAIN to show the types and I get that there are ones that are ALL and I want to see if it can be optimized in some way so that I do not consult all the records.