Mysql to select month-wise record even if data not exist

Question

I wrote a query to get month-wise record in user table as follows

SELECT COUNT( `userID` ) AS total, DATE_FORMAT( `userRegistredDate` , \'%b\' ) AS
MONTH , Y         


        

Answer 1

You may need a table to hold every "month" record. A temp table can do the trick:

drop table if extists temp_months;
create temporary table temp_months
    month date,
    index idx_date(month);
insert into temp_months
    values ('2013-01-31'), ('2013-02-28'), ...

And now, you can left join your data with this newly created temp table:

SELECT 
    COUNT( `userID` ) AS total, 
    DATE_FORMAT( m.month , '%b' ) AS
    MONTH , 
    YEAR( m.month ) AS year
FROM 
    months as m
    left join `users` as u on m.month = last_day(FROM_UNIXTIME(`userRegistredDate`, '%b' )
GROUP BY 
    last_day(m.month);

Notice that you can put the temp table creation (and fill) in a stored procedure.

I use last_day for simplicity, but you are free to use any date in the month that you like, if you join it correctly.

Hope this helps