A View in SQL is a virtual table that is based on the result set of a SELECT query. It does not store data itself but displays data stored in one or more tables.

Key Points about Views

• Acts like a saved query.

• Simplifies complex queries by encapsulating them.

• Can be used to restrict access to specific rows or columns.

• Updates to a view affect the underlying tables (in some cases).

• Improves security and reusability.

Syntax

CREATE VIEW view_name ASSELECT column1, column2, ...FROM table_nameWHERE condition;

Example

CREATE VIEW EmployeeNames ASSELECT EmployeeID, FirstName, LastNameFROM EmployeesWHERE Department = 'Sales';

Now, you can query the view like a table:

SELECT * FROM EmployeeNames;

Notes

• Some views are read-only (especially those with joins, aggregates, or distinct).

• Indexed views (materialized views) store data physically for faster access (supported in some databases).

• You can use ALTER VIEW to modify existing views.

If you want, I can give you examples of complex views or how to update views!