What are views good for?

Question

I\'m just trying to get a general idea of what views are used for in RDBMSes. That is to say, I know what a view is and how to make one. I also know what I\'ve used them f

Answer 1

In addition to what the others have stated, views can also be useful for removing more complecated SQL queries from the application.

As an example, instead of in an application doing:

sql = "select a, b from table1 union select a, b from table2";

You could abstract that to a view:

create view union_table1_table2_v as
select a,b from table1
union
select a,b from table2

and in the app code, simply have:

sql = "select a, b from union_table1_table2_v";

Also if the data structures ever change, you won't have to change the app code, recompile, and redeploy. you would just change the view in the db.