Adding some logic in your MySQL

I'm not an expert in SQL queries, I just know how to do simple queries and the more advanced options I've ever used are DISTINCT, HAVING and GROUP BY.

For the project I'm working on, I had to add some logic to my SQL queries, to concatenate various field and compare them.

Here is, as a reminder, how I've managed to I've managed to get the time spent by comparing two dates:

TIMESTAMPDIFF(SECOND, Timestamp.date, EndTimestamp.date) AS timeSpent

And is practice is never as easy as theory, I didn't really had a timestamp but two string fields instead (one date and one time), so here's how I combined them

TIMESTAMPDIFF(SECOND, CONCAT(Timestamp.date, " ", Timestamp.time), CONCAT(Timestamp.date, " ", Timestamp.time)) AS timeSpent