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What are SQL Views?

Ravi Vishwakarma131 03-Jul-2024

database sql server sql server 2012

Updated on 03-Jul-2024

Ravi Vishwakarma

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Ravi Vishwakarma

03-Jul-2024

SQL Server View is a virtual table derived from one or more tables or other views. It does not store data itself but rather represents a stored SQL query that dynamically retrieves data from its underlying tables whenever the view is queried.

Example

Employees Table:

EmployeeID	FirstName	LastName	DepartmentID	Salary
1	John	Smith	1	50000
2	Jane	Doe	2	60000
3	Michael	Johnson	1	55000
4	Emily	Brown	3	52000

Departments Table:

DepartmentID	DepartmentName
1	HR
2	Finance
3	IT

Now, let's create a view that shows the employees along with their department names:

-- Create a view to show employees with department names
CREATE VIEW EmployeeDetails AS
SELECT e.EmployeeID, e.FirstName, e.LastName, d.DepartmentName, e.Salary
FROM Employees e
JOIN Departments d ON e.DepartmentID = d.DepartmentID;

In this example:

We create a view named EmployeeDetails.
The view selects columns EmployeeID, FirstName, LastName, DepartmentName, and Salary from the Employees table (e) and the Departments table (d).
It joins the Employees table with the Departments table based on the DepartmentID column to retrieve the department name for each employee.
The EmployeeDetails view now provides a consolidated view of employee details along with their department names.

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

-- Query the EmployeeDetails view
SELECT *
FROM EmployeeDetails;

What is SQL Database and why is it so popular?

Write a query to retrieve the total number of employees in each department.

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What are SQL Views?

Ravi Vishwakarma

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