How to write sql view

SQL view is a virtual table based on the underlying table data, used to simplify query and data processing. The steps to create a view include: Determine the basic table and write a SELECT statement to create a view using the CREATE VIEW statement.

SQL View Creation Guide

What is a SQL view?

SQL views are virtual tables that are based on data in one or more basic tables, but do not store actual data by themselves. It provides a way for users to access and process underlying data through a simplified query.

How to create SQL view?

To create a SQL view, use the following syntax:

 <code class="sql">CREATE VIEW  AS ;</code>

is the name of the view you want to create. is a query that selects data from the underlying table, just like in a regular SELECT statement.

Why use SQL views?

There are several reasons for creating SQL views:

• Data Hide: Hide complex queries or connections in the underlying table.
• Data security: Only grant access to views, restricting access to sensitive data.
• Performance optimization: Improve performance by caching frequently used query results.
• Simplified query: Provides users with an easy-to-use interface to access data.
• Data modeling: Create logical data structures for use by applications.

Steps to create a view:

1. Determine the base table: Determine the table to include in the view.
2. Write a SELECT statement: Write a query to select the required data from the underlying table.
3. Create a view: Create a view using the CREATE VIEW statement, specifying the view name and SELECT statement.

Example:

Consider the following basic table:

 <code class="sql">CREATE TABLE Customers ( id INT PRIMARY KEY, name VARCHAR(50), email VARCHAR(50) );</code>

To create a view named CustomerView , displaying only id and name columns, use the following statement:

 <code class="sql">CREATE VIEW CustomerView AS SELECT id, name FROM Customers;</code>

You can now use the CustomerView view to access and process data without having to query the Customers table directly.

 <code class="sql">SELECT * FROM CustomerView;</code>

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