Question

I have a database that looks something like this:

Year    Month        New Visitor?
2011    Jan            Yes
2011    Jan            No
2012    Feb            No
2012    Feb            No
2012    Feb            Maybe

I’d like Yes’s and No’s to be separate columns, per month so I can print it as a chart.I understand that to do this I’ll need a result like this:

Year    Month         Yes       No     Maybe
2011    Jan            1         1       0
2012    Feb            0         2       1

How might I go about this using only MySQL?

Answer 1

Try:

SELECT `Year`, `Month`,
    COUNT(IF (`New Visitor?` = 'Yes', 1, NULL)) AS `Yes`,
    COUNT(IF (`New Visitor?` = 'No', 1, NULL)) AS `No`,
    COUNT(IF (`New Visitor?` = 'Maybe', 1, NULL)) AS `Maybe`
    FROM `table`
    GROUP BY `Year`, `Month`;