What is the use of create or replace in view?
The CREATE VIEW statement creates a new view, or replaces an existing one if the OR REPLACE clause is given. If the view does not exist, CREATE OR REPLACE VIEW is the same as CREATE VIEW. If the view does exist, CREATE OR REPLACE VIEW is the same as ALTER VIEW.
How do I create a view and replace?
The syntax for the CREATE OR REPLACE VIEW Statement in Oracle/PLSQL is: CREATE OR REPLACE VIEW view_name AS SELECT columns FROM table WHERE conditions; view_name. The name of the Oracle VIEW that you wish to create or replace.
What does replace view do?
REPLACE VIEW statement creates a new view, or re-creates the existing view in Teradata.
What’s the difference between create view and alter view?
Notice that the syntax for CREATE VIEW and ALTER VIEW is the same. The ALTER VIEW statement requires a previously existing view with the same name in order to succeed, but the CREATE VIEW statement fails if there is a previously existing view with the same name.
When to use alter view in Oracle Database?
You can also use ALTER VIEW to define, modify, or drop view constraints. This statement does not change the definition of an existing view. To redefine a view, you must use CREATE VIEW with the OR REPLACE keywords. When you issue an ALTER VIEW statement, Oracle Database recompiles the view regardless of whether it is valid or invalid.
When does alter view fail in SQL Server?
The ALTER VIEW statement requires a previously existing view with the same name in order to succeed, but the CREATE VIEW statement fails if there is a previously existing view with the same name. The following script sets up two data sources, such as might be used in the creation of a view.
When to use the alter View statement in Java?
Use the ALTER VIEW statement to explicitly recompile a view that is invalid or to modify view constraints. Explicit recompilation lets you locate recompilation errors before run time.