What is a view??

[thalegend77]

What is the purpose of a view???? How do I use it??? And is it only available in Mysql 5.0???

[jkoopmann]

views are many different things depending how they are used.
the most basic explanation is that a view is another database strucutre, much like a table, that when queried returns rows from the table or set of tables from a pre-defined query. So a view is basically a pre-defined SQL statement that acdesses a set of tables.

for instance a view is created by :
create view my_view as select a.*, b.* from a, b where a.id = b.id

the use of views can be for simplicity (not having to remember the underlying SQL) or as a security measure to hide specific columns from a table from a set of users.
for instance you may have a view the calculates and returns a bonus for each employee. but you may not want to allow users to see the pay rate or salary of each employee.

hope this helps.

[rmiao]

View is available in most rdbms except earlier version of MySql.