mysql get month from timestamp not working

Question

I have a query that pulls the correct data form a db, but it does not return me the month from the timestamp. In the timestamp column I get a null value, even though the tim

Answer 1

You need to convert the timestamp back to a date first, before you can apply the MONTH() function.

MONTH(mdl_quiz_grades.timemodified)

becomes

MONTH(FROM_UNIXTIME(mdl_quiz_grades.timemodified))

Read more about it here.

And as a sidenote, int is enough for a timestamp, bigint is not necessary. A timestamp is a 32bit number, that's why it can hold the maximum date of January 19, 2038.