表查询操作

单表数据查询

select
  u.id,
  u.name
from
  users as u
where
  id = 1
  or (
    b < 5000
    and c in (20, 30)
    and d not in (40, 50)
    and (e between 1 and 2)
    and f like 'a%'
    and g is null
    and h is not null
  )
order by
  i asc nulls last,
  j desc nulls first,
limit
  5
offset
  5

多表数据查询

select
  a.id,
  a.name,
  a.no_id,
  b.name
from
  a,
  b
where
  a.no_id = b.id

select
  a.id,
  a.name,
  a.no_id,
  b.name
from
  a
  inner join b on a.no_id = b.id;

select
  a.id,
  a.name,
  a.no_id,
  b.name
from
  a
  left outer join b on a.no_id = b.id;

select
  a.id,
  a.name,
  a.no_id,
  b.name
from
  a
  right outer join b on a.no_id = b.id;