SQL query - Select * from view or Select col1, col2, … colN from view [duplicate]

Answer 1

select 
column1
,column2
,column3
.
.
.
from Your-View

this one is more optimizer than Using the

select *
from Your View 

Answer 2

NEVER, EVER USE "SELECT *"!!!!

This is the cardinal rule of query design!

There are multiple reasons for this. One of which is, that if your table only has three fields on it and you use all three fields in the code that calls the query, there's a great possibility that you will be adding more fields to that table as the application grows, and if your select * query was only meant to return those 3 fields for the calling code, then you're pulling much more data from the database than you need.

Another reason is performance. In query design, don't think about reusability as much as this mantra:

TAKE ALL YOU CAN EAT, BUT EAT ALL YOU TAKE.

Answer 3

It is best practice to select each column by name. In the future your DB schema might change to add columns that you would then not need for a particular query. I would recommend selecting each column by name.

Answer 4

It depends. Inheritance of views can be a handy thing and easy to maintain (SQL Anywhere):

create view v_fruit as select F.id, S.strain from F key join S; 
create view v_apples as select v_fruit.*, C.colour from v_fruit key join C;