What is a view?

A view in SQL is a virtual table based on the result of a SQL query. It doesn’t store data itself but provides a stored SELECT statement that you can query like a regular table.

🔹 Why Use a View?

• Simplify complex queries
• Enhance security by exposing only certain columns or rows
• Reuse common queries
• Abstract away the complexity of joins or calculated columns

✅ Syntax to Create a View:

CREATE VIEW view_name AS
SELECT column1, column2, ...
FROM table_name
WHERE condition;

🔹 Example: Creating a View

Let’s say you have an employees table, and you want to show only employees from the Sales department.

CREATE VIEW sales_employees AS
SELECT name, department, salary
FROM employees
WHERE department = 'Sales';

Now you can run:

SELECT * FROM sales_employees;

…and it behaves like a table, showing only the filtered data.

🔹 Update a View

You can recreate a view using CREATE OR REPLACE VIEW:

CREATE OR REPLACE VIEW sales_employees AS
SELECT name, department, salary, hire_date
FROM employees
WHERE department = 'Sales';

🔹 Drop a View

DROP VIEW sales_employees;

🔹 Can You Update Data Through a View?

• Yes — if the view is simple (based on one table, no group by, no aggregation).
• But not possible (or limited) with complex views (with JOIN, GROUP BY, DISTINCT, etc.)

🔹 Benefits of Views: