I want to run the following query:
CREATE TABLE dummy AS SELECT x, y, z FROM table1 WHERE y!=0
then I want to do the following:
if z column has a non-null entry do: 1. copy the content of z into A 2. drop z SELECT x,A FROM Dummy
What the second query essentially tries to do is that copy those rows of z into A which have no missing values. My question is how can we write query 2 and if there is a way to merge these two queries into one for optimisation?
Any help/advice much appreciated.