The MYSQL UNION operator is made use of to integrate the result-set of 2 or more SELECT statements. Each SELECT statement within MYSQL UNION must have the very same number of columns. The columns must additionally have comparable data types The columns in each SELECT declaration need to also remain in the very same order
What is Mysql Union? SQL UNION Operator
In this article, you can know about mysql union here are the details below;
MYSQL UNION Syntax
SELECT column_name(s) FROM table1
UNION
SELECT column_name(s) FROM table2;
MYSQL UNION ALL Syntax
The MYSQL UNION driver picks only distinctive worths by default. To enable duplicate values, make use of MYSQL UNION ALL:
SELECT column_name(s) FROM table1
UNION ALL
SELECT column_name(s) FROM table2;
Keep in mind: The column names in the result-set are typically equal to the column names in the very first SELECT statement.
Demo Database
In this tutorial, we will utilize the popular Northwind example data source.
Below is a choice from the “Customers” table:
| CustomerID | CustomerName | ContactName | Address | City | PostalCode | Country |
|---|---|---|---|---|---|---|
| 1 | Alfreds Futterkiste | Maria Anders | Obere Str. 57 | Berlin | 12209 | Germany |
| 2 | Ana Trujillo Emparedados y helados | Ana Trujillo | Avda. de la Constitución 2222 | México D.F. | 05021 | Mexico |
| 3 | Antonio Moreno Taquería | Antonio Moreno | Mataderos 2312 | México D.F. | 05023 | Mexico |
As well as a selection from the “Suppliers” table:
| SupplierID | SupplierName | ContactName | Address | City | PostalCode | Country |
|---|---|---|---|---|---|---|
| 1 | Exotic Liquid | Charlotte Cooper | 49 Gilbert St. | London | EC1 4SD | UK |
| 2 | New Orleans Cajun Delights | Shelley Burke | P.O. Box 78934 | New Orleans | 70117 | USA |
| 3 | Grandma Kelly’s Homestead | Regina Murphy | 707 Oxford Rd. | Ann Arbor | 48104 | USA |
SQL MYSQL UNION Example.
The adhering to SQL statement returns the cities (just distinctive worths) from both the “Customers” and also the “Suppliers” table:
Example.
SELECT City FROM Customers
UNION
SELECT City FROM Suppliers
ORDER BY City;
Note: If some consumers or vendors have the very same city, each city will only be detailed as soon as, since MYSQL picks just distinctive worths. Usage MYSQL UNION ALL to additionally choose to replicate worths!
SQL MYSQL ALL Example
The complying with SQL declaration returns the cities (duplicate worths additionally) from both the “Customers” and also the “Suppliers” table:
Example.
SELECT City FROM Customers
UNION ALL
SELECT City FROM Suppliers
ORDER BY City;
SQL MYSQL UNION With WHERE
The adhering to SQL statement returns the German cities (just unique worths) from both the “Customers” as well as the “Suppliers” table:
Example.
SELECT City, Country FROM Customers
WHERE Country=‘Germany’
UNION
SELECT City, Country FROM Suppliers
WHERE Country=‘Germany’
ORDER BY City;
SQL UNION ALL With WHERE
SELECT City, Country FROM Customers
WHERE Country=‘Germany’
UNION ALL
SELECT City, Country FROM Suppliers
WHERE Country=‘Germany’
ORDER BY City;
MYSQL UNION ALL
SELECT City, Country FROM Customers
WHERE Country=‘Germany’
UNION ALL
SELECT City, Country FROM Suppliers
WHERE Country=‘Germany’
ORDER BY City;
Another MYSQL UNION Example.
The adhering to SQL statement details all consumers and distributors:
Example.
SELECT City FROM Customers
UNION ALL
SELECT City FROM Suppliers
ORDER BY City;
MYSQL UNION
SELECT ‘Customer’ AS Type, ContactName, City, Country
FROM Customers
UNION
SELECT ‘Supplier’, ContactName, City, Country
FROM Suppliers;
Notice the “AS Type” over – it is a pen name. SQL Aliases are utilized to give a table or a column a short-term name. Pen names only exist throughout the inquiry. So, below we have created a temporary column named “Type” that lists whether they get in touch with a person is a “Customer” or a “Supplier.”
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