generate_series() equivalent in MySQL
I need to do a query and join with all days of the year but in my db there isn't a calendar table.
After google-ing I found generate_series()
in PostgreSQL. Does MySQL have anything similar?
My actual table has something like:
date qty
1-1-11 3
1-1-11 4
4-1-11 2
6-1-11 5
But my query has to return:
1-1-11 7
2-1-11 0
3-1-11 0
4-1-11 2
and so on ..
Solution 1:
This is how I do it. It creates a range of dates from 2011-01-01 to 2011-12-31:
select
date_format(
adddate('2011-1-1', @num:=@num+1),
'%Y-%m-%d'
) date
from
any_table,
(select @num:=-1) num
limit
365
-- use limit 366 for leap years if you're putting this in production
The only requirement is that the number of rows in any_table should be greater or equal to the size of the needed range (>= 365 rows in this example). You will most likely use this as a subquery of your whole query, so in your case any_table can be one of the tables you use in that query.
Solution 2:
Enhanced version of solution from @Karolis that ensures it works for any year (including leap years):
select date from (
select
date_format(
adddate('2011-1-1', @num:=@num+1),
'%Y-%m-%d'
) date
from
any_table,
(select @num:=-1) num
limit
366
) as dt
where year(date)=2011