CoderFunda
  • Home
  • About us
    • Contact Us
    • Disclaimer
    • Privacy Policy
    • About us
  • Home
  • Php
  • HTML
  • CSS
  • JavaScript
    • JavaScript
    • Jquery
    • JqueryUI
    • Stock
  • SQL
  • Vue.Js
  • Python
  • Wordpress
  • C++
    • C++
    • C
  • Laravel
    • Laravel
      • Overview
      • Namespaces
      • Middleware
      • Routing
      • Configuration
      • Application Structure
      • Installation
    • Overview
  • DBMS
    • DBMS
      • PL/SQL
      • SQLite
      • MongoDB
      • Cassandra
      • MySQL
      • Oracle
      • CouchDB
      • Neo4j
      • DB2
      • Quiz
    • Overview
  • Entertainment
    • TV Series Update
    • Movie Review
    • Movie Review
  • More
    • Vue. Js
    • Php Question
    • Php Interview Question
    • Laravel Interview Question
    • SQL Interview Question
    • IAS Interview Question
    • PCS Interview Question
    • Technology
    • Other

26 December, 2020

SQL UNION Operator

 Programing Coderfunda     December 26, 2020     SQL Tutorial     No comments   

The SQL UNION Operator

The UNION operator is used to combine the result-set of two or more SELECT statements.

  • Each SELECT statement within UNION must have the same number of columns
  • The columns must also have similar data types
  • The columns in each SELECT statement must also be in the same order

UNION Syntax

SELECT column_name(s) FROM table1
UNION
SELECT column_name(s) FROM table2;

UNION ALL Syntax

The UNION operator selects only distinct values by default. To allow duplicate values, use UNION ALL:

SELECT column_name(s) FROM table1
UNION ALL
SELECT column_name(s) FROM table2;

Note: The column names in the result-set are usually equal to the column names in the first SELECT statement in the UNION.


Demo Database

In this tutorial we will use the well-known Northwind sample database.

Below is a selection from the "Customers" table:

CustomerIDCustomerNameContactNameAddressCityPostalCodeCountry
1

Alfreds FutterkisteMaria AndersObere Str. 57Berlin12209Germany
2Ana Trujillo Emparedados y heladosAna TrujilloAvda. de la Constitución 2222México D.F.05021Mexico
3Antonio Moreno TaqueríaAntonio MorenoMataderos 2312México D.F.05023Mexico

And a selection from the "Suppliers" table:

SupplierIDSupplierNameContactNameAddressCityPostalCodeCountry
1Exotic LiquidCharlotte Cooper49 Gilbert St.LondonEC1 4SDUK
2New Orleans Cajun DelightsShelley BurkeP.O. Box 78934New Orleans70117USA
3Grandma Kelly's HomesteadRegina Murphy707 Oxford Rd.Ann Arbor48104USA


SQL UNION Example

The following SQL statement returns the cities (only distinct values) from both the "Customers" and the "Suppliers" table:

Example

SELECT City FROM Customers
UNION
SELECT City FROM Suppliers
ORDER BY City;
Try it Yourself »

Note: If some customers or suppliers have the same city, each city will only be listed once, because UNION selects only distinct values. Use UNION ALL to also select duplicate values!


SQL UNION ALL Example

The following SQL statement returns the cities (duplicate values also) from both the "Customers" and the "Suppliers" table:

Example

SELECT City FROM Customers
UNION ALL
SELECT City FROM Suppliers
ORDER BY City;
Try it Yourself »

SQL UNION With WHERE

The following SQL statement returns the German cities (only distinct values) from both the "Customers" and the "Suppliers" table:

Example

SELECT City, Country FROM Customers
WHERE Country='Germany'
UNION
SELECT City, Country FROM Suppliers
WHERE Country='Germany'
ORDER BY City;
Try it Yourself »

SQL UNION ALL With WHERE

The following SQL statement returns the German cities (duplicate values also) from both the "Customers" and the "Suppliers" table:

Example

SELECT City, Country FROM Customers
WHERE Country='Germany'
UNION ALL
SELECT City, Country FROM Suppliers
WHERE Country='Germany'
ORDER BY City;
Try it Yourself »

Another UNION Example

The following SQL statement lists all customers and suppliers:

Example

SELECT 'Customer' AS Type, ContactName, City, Country
FROM Customers
UNION
SELECT 'Supplier', ContactName, City, Country
FROM Suppliers;
Try it Yourself »

Notice the "AS Type" above - it is an alias. SQL Aliases are used to give a table or a column a temporary name. An alias only exists for the duration of the query. So, here we have created a temporary column named "Type", that list whether the contact person is a "Customer" or a "Supplier".

  • Share This:  
  •  Facebook
  •  Twitter
  •  Google+
  •  Stumble
  •  Digg
Email ThisBlogThis!Share to XShare to Facebook

Related Posts:

  • SQL Joins SQL JOINA JOIN clause is used to combine rows from two or more tables, based on a related column between them.Let's look at a selection from the… Read More
  • SQL RIGHT JOIN Keyword SQL RIGHT JOIN KeywordThe RIGHT JOIN keyword returns all records from the right table (table2), and the matched records from the left table (tab… Read More
  • SQL INNER JOIN Keyword SQL INNER JOIN KeywordThe INNER JOIN keyword selects records that have matching values in both tables.INNER JOIN SyntaxSELECT column_name(s… Read More
  • SQL FULL OUTER JOIN Keyword SQL FULL OUTER JOIN KeywordThe FULL OUTER JOIN keyword returns all records when there is a match in left (table1) or right (table2) table records.Not… Read More
  • SQL LEFT JOIN KeywordSQL LEFT JOIN KeywordThe LEFT JOIN keyword returns all records from the left table (table1), and the matched records from the right table (table2). Th… Read More
Newer Post Older Post Home

0 comments:

Post a Comment

Thanks

Meta

Popular Posts

  • Write API Integrations in Laravel and PHP Projects with Saloon
    Write API Integrations in Laravel and PHP Projects with Saloon Saloon  is a Laravel/PHP package that allows you to write your API integratio...
  • Features CodeIgniter
    Features CodeIgniter There is a great demand for the CodeIgniter framework in PHP developers because of its features and multiple advan...
  • Laravel Breeze with PrimeVue v4
    This is an follow up to my previous post about a "starter kit" I created with Laravel and PrimeVue components. The project has b...
  • Fast Excel Package for Laravel
      Fast Excel is a Laravel package for importing and exporting spreadsheets. It provides an elegant wrapper around Spout —a PHP package to ...
  • Send message via CANBus
    After some years developing for mobile devices, I've started developing for embedded devices, and I'm finding a new problem now. Th...

Categories

  • Ajax (26)
  • Bootstrap (30)
  • DBMS (42)
  • HTML (12)
  • HTML5 (45)
  • JavaScript (10)
  • Jquery (34)
  • Jquery UI (2)
  • JqueryUI (32)
  • Laravel (1017)
  • Laravel Tutorials (23)
  • Laravel-Question (6)
  • Magento (9)
  • Magento 2 (95)
  • MariaDB (1)
  • MySql Tutorial (2)
  • PHP-Interview-Questions (3)
  • Php Question (13)
  • Python (36)
  • RDBMS (13)
  • SQL Tutorial (79)
  • Vue.js Tutorial (68)
  • Wordpress (150)
  • Wordpress Theme (3)
  • codeigniter (108)
  • oops (4)
  • php (853)

Social Media Links

  • Follow on Twitter
  • Like on Facebook
  • Subscribe on Youtube
  • Follow on Instagram

Pages

  • Home
  • Contact Us
  • Privacy Policy
  • About us

Blog Archive

  • September (100)
  • August (50)
  • July (56)
  • June (46)
  • May (59)
  • April (50)
  • March (60)
  • February (42)
  • January (53)
  • December (58)
  • November (61)
  • October (39)
  • September (36)
  • August (36)
  • July (34)
  • June (34)
  • May (36)
  • April (29)
  • March (82)
  • February (1)
  • January (8)
  • December (14)
  • November (41)
  • October (13)
  • September (5)
  • August (48)
  • July (9)
  • June (6)
  • May (119)
  • April (259)
  • March (122)
  • February (368)
  • January (33)
  • October (2)
  • July (11)
  • June (29)
  • May (25)
  • April (168)
  • March (93)
  • February (60)
  • January (28)
  • December (195)
  • November (24)
  • October (40)
  • September (55)
  • August (6)
  • July (48)
  • May (2)
  • January (2)
  • July (6)
  • June (6)
  • February (17)
  • January (69)
  • December (122)
  • November (56)
  • October (92)
  • September (76)
  • August (6)

  • Failed to install 'cordova-plugin-firebase': CordovaError: Uh oh - 9/21/2024
  • pyspark XPath Query Returns Lists Omitting Missing Values Instead of Including None - 9/20/2024
  • SQL REPL from within Python/Sqlalchemy/Psychopg2 - 9/20/2024
  • MySql Explain with Tobias Petry - 9/20/2024
  • How to combine information from different devices into one common abstract virtual disk? [closed] - 9/20/2024

Laravel News

  • Manipulate Image URLs in Laravel with the Image Transform Package - 6/19/2025
  • Handle Nested Arrays Elegantly with Laravel's fluent() Helper - 6/18/2025
  • Laravel 12.19 Adds a useEloquentBuilder Attribute, a FailOnException Queue Middleware, and More - 6/18/2025
  • Test Deferred Operations Easily with Laravel's withoutDefer Helper - 6/18/2025
  • Larallow is a Permissions Package With Support for Scopes - 6/17/2025

Copyright © 2025 CoderFunda | Powered by Blogger
Design by Coderfunda | Blogger Theme by Coderfunda | Distributed By Coderfunda