Create a Postgres Table

Insert Data into Postgres Tables

Filter Data in a Postgres Table with Query Statements

Update Data in Postgres

Delete Postgres Records

Group and Aggregate Data in Postgres

Sort Postgres Tables

Ensure Uniqueness in Postgres

Use Foreign Keys to Ensure Data Integrity in Postgres

Create Foreign Keys Across Multiple Fields in Postgres

Enforce Custom Logic with Check Constraints in Postgres

Speed Up Postgres Queries with Indexes

Find Intersecting Data with Postgres’ Inner Join

Select Distinct Data in Postgres

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How do I see a list of my Facebook friends sorted by the number of friends they have, and then sorted alphabetically to break ties? Sorting data helps us to answer important business questions. In this lesson, we’ll learn how to do it in Postgres.

[00:00] Today we're sorting data. We're going to sort some friends by the number of friends they have in our Facebook type app. By default, this is always ascending, so we're going to start with the lowest number of friends and move up to the highest number of friends.

[00:16] If we want to change to descending, we will append the the descending descriptor here, but I like it ascending to start. We see here, though, that Sophia and Andrew have a tie for the number of friends they have. If they do, we can specify another way to sort them, because without it, we don't have that information. It's just going to default to using this ID column.

[00:43] We might prefer to sort by the name. Now Andrew comes before Sophia, so Andrew will sort higher. We can also add descending to both of these to specify that we want it to go in the exact opposite order.

[00:58] Now we'll start with the highest number of friends, move through to the lowest number of friends, and also, in name ties, we'll go in reverse alphabetical order. That doesn't seem to make sense, so we'll leave this. Now Andrew beats Sophia, but the person with the most friends is still going to be listed first in our list. That's orderized.

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Get Started With PostgreSQL

Sort Postgres Tables

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