MySQL : Views

In MySQL, a view is a virtual table that is defined by a SQL query. It represents the result set of a query and can be used like a regular table in most SQL operations. Views provide a way to simplify complex queries, encapsulate logic, and control access to data by exposing only selected columns or rows.

Here's how you can create a view in MySQL:

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

• view_name is the name of the view you want to create.
• column1, column2, etc. are the columns you want to include in the view.
• table_name is the name of the table you're querying.
• condition is an optional condition to filter the rows.

For example, let's say you have a table named employees with columns id, first_name, last_name, and salary, and you want to create a view that displays only the id, first_name, and salary columns for employees with a salary greater than $50,000:

CREATE VIEW high_salary_employees AS
SELECT id, first_name, salary
FROM employees
WHERE salary > 50000;
 

After creating the view, you can query it like a regular table:

SELECT * FROM high_salary_employees;
 

You can also update, delete, or insert data into a view under certain conditions, depending on the complexity of the view and its underlying query.

Views provide a convenient way to simplify complex queries, standardize data access, and enhance security by restricting access to specific columns or rows. They can be particularly useful in scenarios where you frequently need to query the same subset of data from multiple tables or when you want to abstract away complex joins or calculations.