generate_series() method fails in Redshift

Question

When I run the SQL Query:

 select generate_series(0,g)
 from ( select date(date1) - date(date2) as g from mytable ;

It returns an error:

Answer 1

You will need to use functions that are supported by the leader node. The trick is to use the row_number() function from any table that you want. Let's say that we want to generate a date-series from 10 days ago up tp now:

   SELECT DATEADD('day', -n, (CURRENT_DATE+1)) AS generated_date
   FROM (SELECT ROW_NUMBER() OVER () AS n FROM my_table LIMIT 10) n
   ORDER BY generated_date DESC

And we get:

generated_date
2020-06-24 00:00:00
2020-06-23 00:00:00
2020-06-22 00:00:00
2020-06-21 00:00:00
2020-06-20 00:00:00
2020-06-19 00:00:00
2020-06-18 00:00:00
2020-06-17 00:00:00
2020-06-16 00:00:00
2020-06-15 00:00:00