Oracle and PostgreSQL Query Difference

10 Major Oracle and PostgreSQL Query Difference

Oracle	PostgreSQL
select * from tablename;	select * from tablename;
desc tablename	-----(select itself desc coming)
nvl(sum,0)	coalesce(sum,0)
decode(a,1,aa,bb)	(case when a=1 then aa else bb end)
oracle supports ‘’ or null (both are same)	In postgresql  ‘’ and null both are different
rownum	limit
rowed	ctid
Date shows dd/mmm/yyyy	yyyy/mmm/dd
Auto cast from String to Date	cast(d as date)
String to integer to_number(a)	cast ( a as numeric)