Software Applications Programming Errors and solutions.

Difference between  alias and synonym in sql Both are different in all manner not only syntactically Synonym is 1. It is a database object 2. It may be Public or private 3. It is permanent until dropped 4. create [public] synonyms syn_name for [Existed database object]; like create synonym emp1  for hr.employees; Alias is 1. It is not a database object. 2. It will alway private to query 3. It temporary to that query.It to used to provide a name It is generally used to provide a meaning-full heading or column name or table name that is long or inconvenient to type in Query 4. take a example select rownum as rank,e.* from emp1 e; here rank and e is alias where as emp1 is synonym