devxlogo

Differences Between Join Types

Differences Between Join Types

Question:
What are the differences between LEFT, RIGHT, INNER and OUTER JOINS?

Answer:
An INNER JOIN is the most common type: It combines all the data from the tables specified and eliminates the rows that do not meet the criteria specified in the WHERE clause.

LEFT and RIGHT JOINs are types of OUTER JOINs. In general, an OUTER JOIN is one that preserves all the rows in one of the tables specified in the FROM clause, even if there are no matching rows with the other table. A LEFT OUTER JOIN means that the preserved table is the one specified on the left side of the equation; a RIGHT OUTER JOIN means that the preserved table is the one specified on the right side of the equation. A FULL OUTER JOIN preserves the tables on both sides of the equation.

See also  5 Tips for Working With an Onsite Interpreter
devxblackblue

About Our Editorial Process

At DevX, we’re dedicated to tech entrepreneurship. Our team closely follows industry shifts, new products, AI breakthroughs, technology trends, and funding announcements. Articles undergo thorough editing to ensure accuracy and clarity, reflecting DevX’s style and supporting entrepreneurs in the tech sphere.

See our full editorial policy.

About Our Journalist