Explain natural join operation.
Database Management System
Computer Science Engineering
663
Krishav
A natural join is a type of join operation that creates a new table by combining rows from two or more tables based on the common columns between them. The common columns are columns that have the same name and data type in both tables.
For example, let's say we have two tables: a Customers
table and an Orders
table. The Customers
table has the following columns:
The Orders
table has the following columns:
We can join these two tables together using a natural join to create a new table that contains all of the rows from both tables, along with the common columns from both tables. The following SQL query would perform a natural join on the Customers
and Orders
tables:
SQL
SELECT
Customers.CustomerID,
Customers.CustomerName,
Customers.CustomerAddress,
Orders.OrderID,
Orders.OrderDate,
Orders.OrderAmount
FROM
Customers
NATURAL JOIN
Orders;
The result of this query would be a new table that contains the following rows:
Code snippet
CustomerID | CustomerName | CustomerAddress | OrderID | OrderDate | OrderAmount
----------+-------------+----------------+--------+--------------+---------
1 | John Smith | 123 Main Street | 1 | 2023-06-06 | 100.00
2 | Jane Doe | 456 Elm Street | 2 | 2023-06-07 | 200.00
3 | Mary Jones | 789 Oak Street | 3 | 2023-06-08 | 300.00
As you can see, the natural join has combined the rows from both tables, and the common columns from both tables have been included in the new table.
Natural joins are a powerful tool that can be used to combine data from multiple tables. They are often used to create reports or to perform analysis on data.