The SQL TRUNCATE TABLE command is used to delete complete data from an existing table.
You can also use DROP TABLE command to delete complete table but it would remove complete table structure form the database and you would need to re-create this table once again if you wish you store some data.
Syntax: The basic syntax of TRUNCATE TABLE is as follows:
TRUNCATE TABLE table_name;A view is nothing more than a SQL statement that is stored in the database with an associated name. A view is actually a composition of a table in the form of a predefined SQL query.
A view can contain all rows of a table or select rows from a table. A view can be created from one or many tables which depends on the written SQL query to create a view.
Views, which are kind of virtual tables, allow users to do the following:
Structure data in a way that users or classes of users find natural or intuitive.
Restrict access to the data such that a user can see and (sometimes) modify exactly what they need and no more.
Summarize data from various tables which can be used to generate reports.
Creating Views: Database views are created using the CREATE VIEW statement. Views can be created from a single table, multiple tables, or another view.
To create a view, a user must have the appropriate system privilege according to the specific implementation.
The basic CREATE VIEW syntax is as follows:
CREATE VIEW view_name AS
SELECT column1, column2.....
FROM table_name
WHERE [condition];You can include multiple tables in your SELECT statement in very similar way as you use them in normal SQL SELECT query.
CREATE VIEW CUSTOMERS_VIEW AS
SELECT name, age
FROM CUSTOMERS;