Return the data in a specific order

SELECT * | <value1>, <value2>
FROM <table_name>
ORDER BY <field1> ASC | DESC;

It's like saying: "Hey, PostgreSQL; please can you find this information for me? It's in this table in this schema. When you find it, please sort it by something and read it back in that order"

For example, if we wanted to return all products and order by least popular:

SELECT product_id, product_category, product_item, product_variety, popularity
FROM "sequel-mart-schema"."Products"
ORDER BY popularity;

Or most popular:

SELECT product_id, product_category, product_item, product_variety, popularity
FROM "sequel-mart-schema"."Products"
ORDER BY popularity DESC;

Note the DESC on the end of the second statement.

• DESC shows we are sorting by popularity in descending order.
• We could add ASC at the end of the first statement but ORDER BY orders ascending by default so this is not required

Combining with WHERE...

If we want to know the highest and lowest values for a specific subset of the data we can combine them with the WHERE clause

Advice for usage

• While ORDER BY is useful, it is discouraged for large-scale production environments:
• Sorting tends to be resource intensive on very large tables
• It is a bottleneck in the execution plan
• Front-end systems are often better at sorting data once it's been pulled in