Question

A join that is based upon data having equivalent data in common columns is known as a(n) ____________________ join.

a) Inner
b) Outer
c) Cross
d) Self

Answer 1

An inner join is used to combine rows from two tables based on a related column between them. It returns only those records that have matching values in both tables. For instance, joining Customers to Orders tables on CustomerID will return only the customers who have made orders.

Step-by-step explanation:

A join that is based upon data having equivalent data in common columns is known as a(n) inner join. This is one of the most common types of joins used in SQL when you want to retrieve records that have matching values in both tables being joined.

For example, if you have two tables, Customers and Orders, and you want to find all customers who have placed an order, you would use an inner join to combine the data. The SQL statement may look something like this:

SELECT Customers.CustomerName, Orders.OrderID
FROM Customers
INNER JOIN Orders
ON Customers.CustomerID = Orders.CustomerID;

This SQL query would return a result set that contains customer names and order IDs, but only for those entries where a customer ID is present in both the Customers and Orders tables.