Can if-then-else logic be done in Redshift?

Question

I am a newbie to RedShift but experienced with MSSQL. I was wondering if there's any way to write an if-then-else logic in Redshift?

Basically I want to run this logic in Redshift:

if ((select count(*) from a) - (select count(*) from b)) = 0 then 
   drop table a;

Thanks in advance!

Answer 1

Redshift doesn't support procedural statements, so you handle this best in your application code. If you must do it inside of SQL, something along the lines of this may help:

delete from a where (select count(*) from a) = (select count(*) from b);

This doesn't drop the table but deletes all rows from it when your condition is met.