Lesson 9.4

Formatting SQL Queries for Readability

Clean formatting doesn't change what a query returns, but it makes mistakes far easier to spot.

A query crammed onto one line still runs, but good luck spotting the bug in it. Formatting is a debugging tool: when each clause sits on its own line, a missing comma or a misplaced condition jumps out.

The habits are simple: one column per line, each clause (FROM, JOIN, GROUP BY) starting a new line, the join condition indented under itsJOIN, and clear aliases. The result never changes, only your ability to read it.

Pattern

select col_a,
       col_b,
       count(*) as n
from table_one as t
join table_two as u
  on t.id = u.t_id
group by col_a, col_b
order by n desc

Schema · Garden ShopTable · customers9 columns · 20 rows

Table · customers

One row per customer. Some customers have no phone on file.

9 columns · 20 rows

customer_id intfirst_name textlast_name textemail textphone textcity textstate textsignup_date dateis_active bool

Your task

The starter is a correct query crammed onto a single line. Reformat it for readability. It should still return each customer'sfirst_name, last_name, and order count asorders, most orders first. The rows won't change; only the layout will.

SQL Workbench

query.sqlgarden_shop · SQL engine loading

⌘↵ to run

Expected answer