What is the difference between the INNER JOIN and the OUTER JOIN in SQL?

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Aryan Kumar · Answer

Sure. Here are the key differences between inner joins and outer joins in SQL:

Inner Join	Outer Join
Returns rows where there is a match in both tables.	Returns all rows from the left table, even if there is no match in the right table.
The ON clause is used to specify the join condition.	The ON clause is used to specify the join condition, and the OUTER keyword is used to specify the type of outer join.
The WHERE clause can be used to filter the results of the join.	The WHERE clause can be used to filter the results of the join, but it cannot be used to change the rows that are returned by the outer join.
The INNER JOIN keyword is used to create an inner join.	The LEFT JOIN, RIGHT JOIN, and FULL JOIN keywords are used to create outer joins.

Here are some examples of how inner joins and outer joins can be used:

Inner join: To find all customers who have placed an order, you would use an inner join on the customers and orders tables. The ON clause would specify that the customer_id column in the customers table matches the customer_id column in the orders table.
Left outer join: To find all customers, regardless of whether they have placed an order, you would use a left outer join on the customers and orders tables. The ON clause would specify that the customer_id column in the customers table matches the customer_id column in the orders table. The left outer join would return all rows from the customers table, even if there is no match in the orders table.
Right outer join: To find all orders, regardless of whether they have a corresponding customer, you would use a right outer join on the customers and orders tables. The ON clause would specify that the customer_id column in the customers table matches the customer_id column in the orders table. The right outer join would return all rows from the orders table, even if there is no match in the customers table.
Full outer join: To find all customers and orders, regardless of whether there is a match between them, you would use a full outer join on the customers and orders tables. The ON clause would specify that the customer_id column in the customers table matches the customer_id column in the orders table. The full outer join would return all rows from both tables, even if there is no match between them.

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What is the difference between the INNER JOIN and the OUTER JOIN in SQL?

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