{"id":12398,"date":"2021-01-12T13:32:07","date_gmt":"2021-01-12T21:32:07","guid":{"rendered":"https:\/\/careerkarma.com\/blog\/?p=12398"},"modified":"2023-12-01T04:08:01","modified_gmt":"2023-12-01T12:08:01","slug":"sql-inner-join-operator","status":"publish","type":"post","link":"https:\/\/careerkarma.com\/blog\/sql-inner-join-operator\/","title":{"rendered":"SQL INNER JOIN: A Complete Guide"},"content":{"rendered":"\n

The SQL INNER JOIN statement returns rows with exact values in two columns across two tables. You can join a table across one or multiple columns. JOIN statements connect two database tables and compare their contents.<\/em><\/p>\n\n\n\n

There may be times when you want to get data from two or more tables at the same time and combine the result.<\/p>\n\n\n\n

For example, you may want to get a list of products and the names of suppliers who have supplied those products. The information for product names and supplier names is in two tables.<\/p>\n\n\n\n

This is where SQL<\/em> joins come in. By using the join<\/em> condition, you are able to combine information from multiple tables intoe following: one result set. The SQL INNER JOIN is a type of join that returns records who have matching column values in two tables. In this tutorial, we are going to discuss how to use an INNER JOIN.<\/em><\/p>\n\n\n\n

SQL INNER JOIN<\/h2>\n\n\n\n

The SQL INNER JOIN retrieves all the records with column values that appear in two specified tables. An INNER JOIN statement uses the ON keyword to match the data across the two tables.<\/p>\n\n\n\n

The INNER JOIN<\/em> is the most common type of SQL join<\/em>. The operator returns records that have a match in both tables.<\/p>\n\n\n\n

Let’s take a look at the syntax of the INNER JOIN<\/em> keyword:<\/p>\n\n\n\n

SELECT name<\/p>\n\n\n\n

FROM customers<\/p>\n\n\n\n

INNER JOIN plans<\/p>\n\n\n\n

ON customers.plan_id = plans.id;<\/p>\n\n\n\n

This query combines rows from the “customers” and “plans” tables. It returns a list of all customers with a “plan_id” equal to any ID In the “plans” table.<\/p>\n\n\n\n

We use the INNER JOIN clause to join our tables. The ON keyword comes after the name of the table we join. You can specify multiple conditions after the ON keyword by separating them with commas.<\/p>\n\n\n\n

INNER JOIN SQL Example<\/h2>\n\n\n\n

Right now, we have an employee database that stores the department ID of each employee in the employees<\/em> table. We created this table with an SQL CREATE TABLE statement<\/a>. The department names are stored in a separate table called company_departments<\/em>.<\/p>\n\n\n\n

Here is the employees<\/em> table:<\/p>\n\n\n\n