Oracle SQL Syntaxe: Select

Question

L'instruction SQL suivante est-elle valide dans Oracle SQL?

1)

select 1 

2)

select test from (select 1 as test) 

3)

select test from (select 1 as test) s 

Merci à l'avance!

Best, Will

Answer 1

Aucun d'entre eux sont valides. Ce sont les instructions correctes:

1)

select 1 from dual 

2)

select test from (select 1 as test from dual) 

3)

select test from (select 1 as test from dual) s 
-- or also 
select s.test from (select 1 as test from dual) s