使用子查询Oracle SQL进行数据透视

Question

I am trying to use pivot to display my information. I want to use a subquery to select the columns in the report:

select * from 
(select continent, country, population
 from continents, countries
 where continents.id=countries.id
 )
 pivot (sum(population) for country in (select distinct country from countries)

I keep getting an error when I try to use a subquery to get the list of countries.

I tried using pivot XML but that didn't work either since it returned meaningless xml code. I want to see the actual numbers!

Answer 1

You can't use result of subquery in PIVOT clause as columns need to be defined statically. But you can generate dynamic SQL using results of your subquery and then execute it via execute immediate.