MySQL
- Introduction To MySQL
- MySQL RDBMS
- MySQL SQL
- MySQL SELECT Statement
- MySQL WHERE Clause
- MySQL AND, OR And NOT Operators
- MySQL ORDER BY Keyword
- MySQL INSERT INTO Statement
- MySQL NULL Values
- MySQL UPDATE Statement
- MySQL DELETE Statement
- MySQL LIMIT Clause
- MySQL MIN() And MAX() Functions
- MySQL COUNT(), AVG() And SUM() Functions
- MySQL LIKE Operator
- MySQL Wildcards
- MySQL IN Operator
- MySQL BETWEEN
- MySQL Aliases
- MySQL Joins
- MySQL INNER JOIN Keyword
- MySQL LEFT JOIN Keyword
- MySQL RIGHT JOIN Keyword
- MySQL CROSS JOIN Keyword
- MySQL Self Join
- MySQL UNION Operator
- MySQL GROUP BY Statement
- MySQL HAVING Clause
- MySQL EXISTS Operator
- MySQL ANY And ALL Operators
- MySQL INSERT INTO SELECT Statement
- MySQL CASE Statement
- MySQL NULL Functions
- MySQL Comments
- MySQL Operators
- MySQL CREATE DATABASE Statement
- MySQL DROP DATABASE Statement
- MySQL CREATE TABLE Statement
- MySQL DROP TABLE Statement
- MySQL ALTER TABLE Statement
- MySQL Constraints
- MySQL NOT NULL Constraint
- MySQL UNIQUE Constraint
- MySQL PRIMARY KEY Constraint
- MySQL FOREIGN KEY Constraint
- MySQL CHECK Constraint
- MySQL DEFAULT Constraint
- MySQL CREATE INDEX Statement
- MySQL AUTO INCREMENT Field
- MySQL Working With Dates
- MySQL Views
- MySQL Data Types
- MySQL Functions
MySQL Views
MySQL CREATE VIEW Statement
In SQL, a view is a virtual table based on the result-set of an SQL statement.
A view contains rows and columns, just like a real table. The fields in a view are fields from one or more real tables in the database.
You can add SQL statements and functions to a view and present the data as if the data were coming from one single table.
A view is created with the CREATE VIEW statement.
CREATE VIEW Syntax
CREATE VIEW view_name AS
SELECT column1, column2, ...
FROM table_name
WHERE condition;
SELECT column1, column2, ...
FROM table_name
WHERE condition;
MySQL CREATE VIEW Examples
The following SQL creates a view that shows all customers from Brazil:
CREATE VIEW [Brazil Customers] AS
SELECT CustomerName, ContactName
FROM Customers
WHERE Country = 'Brazil';
SELECT CustomerName, ContactName
FROM Customers
WHERE Country = 'Brazil';
We can query the view above as follows:
SELECT * FROM [Brazil Customers];
The following SQL creates a view that selects every product in the "Products" table with a price higher than the average price:
CREATE VIEW [Products Above Average Price] AS
SELECT ProductName, Price
FROM Products
WHERE Price > (SELECT AVG(Price) FROM Products);
SELECT ProductName, Price
FROM Products
WHERE Price > (SELECT AVG(Price) FROM Products);
We can query the view above as follows:
SELECT * FROM [Products Above Average Price];
MySQL Updating A View
A view can be updated with the CREATE OR REPLACE VIEW statement.
CREATE OR REPLACE VIEW Syntax
CREATE OR REPLACE VIEW view_name AS
SELECT column1, column2, ...
FROM table_name
WHERE condition;
The following SQL adds the "City" column to the "Brazil Customers" view:SELECT column1, column2, ...
FROM table_name
WHERE condition;
CREATE OR REPLACE VIEW [Brazil Customers] AS
SELECT CustomerName, ContactName, City
FROM Customers
WHERE Country = 'Brazil';
SELECT CustomerName, ContactName, City
FROM Customers
WHERE Country = 'Brazil';
MySQL Dropping A View
A view is deleted with the DROP VIEW statement.
DROP VIEW Syntax
DROP VIEW view_name;
The following SQL drops the "Brazil Customers" view:
DROP VIEW [Brazil Customers];