INNER JOIN in Postgres
December 17, 2020

The INNER JOIN keyword selects records that have matching values in both tables.

Basically, it looks like this.

Inner Join in PostgreSQL

The highlighted blue part from the image above is our query results when we apply INNER JOIN between 2 tables.


SELECT a.column2, b.column2
FROM table a
INNER JOIN table b
ON a.column = b.column;

I am using alias as well in the syntax. You can use name of the table instead of alias. Alias makes it better to write the query. Learn more about alias in this post:

Column And Table Alias In Postgres

INNER JOIN Query Example 2 tables

I am using the database for all examples. It is available on my Github public repo

SELECT c.contact_name, o.order_date 
FROM customers c INNER JOIN orders o
ON c.customer_id = o.customer_id

contact_name.  order_date 
"Paul Henriot"	"1996-07-04"
"Karin Josephs"	"1996-07-05"
"Mario Pontes"	"1996-07-08"
830 rows

INNER JOIN Query Example 3 tables

SELECT c.contact_name, o.order_date, COUNT(od.product_id)
FROM customers c INNER JOIN orders o ON c.customer_id = o.customer_id
INNER JOIN order_details od ON od.order_id = o.order_id
GROUP BY od.order_id, c.contact_name, o.order_date

contact_name.    order_date.   count
"Paolo Accorti"	"1997-10-20"	2
"José Pedro Freyre"	"1997-05-28"	4
"Paula Wilson"	"1998-01-07"	1
830 rows

Of course, we can use ORDER BY and sort the query results the way we want.


Leave a Reply

Most Read

#1 How to check if radio button is checked or not using JavaScript? #2 How to set opacity or transparency using CSS? #3 Pagination in CSS with multiple examples #4 How to make HTML form interactive and using CSS? #5 How to uninstall Cocoapods from the Mac OS? #6 Solution to “TypeError: ‘x’ is not iterable” in Angular 9

Recently Posted

Feb 25 How to set default timezone using PHP? Feb 24 WordPress: How to loop through a repeater field in ACF? Feb 24 How to get ACF values from custom post type? Feb 24 WordPress get_posts Examples Feb 24 How to modify the latest post array using get_posts() in WordPress? Feb 22 WordPress: How to get ACF field values from another post?

You might also like these

List of social media icon logo color codes in HEXMiscHow to get Current Year, Month and Date in JavaScript?JavaScriptHow to create a sticky menu pin using CSS?CSSHow to deploy Angular App on Dreamhost or Amazon S3 or firebase?Angularaddcslashes() and addslashes() String Functions in PHPPHPFew more :nth-child examples in CSSCSS