单个连接条件应该与连接在同一行

-- Good
select
    users.email,
    sum(charges.amount) as total_revenue
from users
inner join charges on users.id = charges.user_id
group by email

-- Bad
select
    users.email,
    sum(charges.amount) as total_revenue
from users
inner join charges
on users.id = charges.user_id
group by email

当你有多个连接条件时，将每一个条件放在它们自己的缩进行上：

-- Good
select
    users.email,
    sum(charges.amount) as total_revenue
from users
inner join charges on 
    users.id = charges.user_id and
    refunded = false
group by email