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SQL Views

Structured Query Language (SQL) is a programming language used to manage and manipulate relational databases. SQL Views are virtual tables that are created based on the result set of a SELECT statement. Views are used to simplify complex queries and to provide a layer of abstraction between the user and the underlying database tables. In this article, we will discuss SQL Views in detail.

Brief Explanation of SQL Views

SQL Views are virtual tables that are created based on the result set of a SELECT statement. Views are used to simplify complex queries and to provide a layer of abstraction between the user and the underlying database tables. Views can be used to hide the complexity of the underlying database schema and to provide a simplified view of the data to the user.

Views can be used to perform the following tasks:

  • Hide the complexity of the underlying database schema
  • Provide a simplified view of the data to the user
  • Restrict access to sensitive data
  • Combine data from multiple tables into a single view
  • Provide a consistent view of the data to the user

Code Examples

Let's take a look at some code examples to better understand SQL Views.

Creating a View

The following code creates a view that selects all columns from the "customers" table:


CREATE VIEW customer_view AS
SELECT *
FROM customers;

The "customer_view" view can now be used to query the "customers" table:


SELECT * FROM customer_view;

Restricting Access to Sensitive Data

The following code creates a view that selects only the "customer_id" and "customer_name" columns from the "customers" table:


CREATE VIEW customer_names AS
SELECT customer_id, customer_name
FROM customers;

The "customer_names" view can now be used to query the "customers" table, but only the "customer_id" and "customer_name" columns will be returned:


SELECT * FROM customer_names;

Combining Data from Multiple Tables

The following code creates a view that combines data from the "customers" and "orders" tables:


CREATE VIEW customer_orders AS
SELECT customers.customer_id, customers.customer_name, orders.order_id, orders.order_date
FROM customers
INNER JOIN orders
ON customers.customer_id = orders.customer_id;

The "customer_orders" view can now be used to query the combined data from the "customers" and "orders" tables:


SELECT * FROM customer_orders;

Conclusion

SQL Views are virtual tables that are created based on the result set of a SELECT statement. Views are used to simplify complex queries and to provide a layer of abstraction between the user and the underlying database tables. Views can be used to hide the complexity of the underlying database schema and to provide a simplified view of the data to the user. SQL Views are a powerful tool for managing and manipulating relational databases.

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