Question

如何简化此查询？不幸的是，这不起作用

$Query = mysqli_query($conn, "SELECT * FROM order_number where trans_id NOT IN (SELECT order_no from billing)
                                       AND NOT IN(SELECT order_no from pending)
                                       AND NOT IN(SELECT order_no from on_process)
                                       AND NOT IN(SELECT order_no from finished)");

还有其他方法吗？我试图打印trans_id行，如果它不在开票，待处理，on_process和完成。

Answer 1

SELECT * FROM order_number 
where trans_id NOT IN 
(
   SELECT order_no from billing
   union 
   SELECT order_no from pending
   union 
   SELECT order_no from on_process
   union
   SELECT order_no from finished
)

或当你尝试它时

SELECT * FROM order_number 
where trans_id NOT IN (SELECT order_no from billing)
  AND trans_id NOT IN (SELECT order_no from pending)
  AND trans_id NOT IN (SELECT order_no from on_process)
  AND trans_id NOT IN (SELECT order_no from finished)

Answer 2

没有理由“简化”查询。通过四个子查询中的表的适当索引，它应该非常有效。如果orderno在任何表格中都可以NULL，那么我建议改为使用not exists：

SELECT *
FROM order_number  o
WHERE NOT EXISTS (select order_no from billing where b.order_no = o.trans_id) AND
      NOT EXISTS (select order_no from pending p where p.order_no = o.trans_id) AND
      NOT EXISTS (select order_no from on_process op where op.order_no = o.trans_id) AND
      NOT EXISTS (select order_no from finished f where f.order_no = o.trans_id);

正确的索引包括：billing(order_no)，pending(order_no)，finished(order_no)和on_process(order_no)。

Answer 3

您可以在表上进行左连接，并过滤掉没有匹配记录的记录：

select
  n.*
from
  order_number n
  left join billing b on b.order_no = n.trans_id
  left join pending p on p.order_no = n.trans_id
  left join on_process o on o.order_no = n.trans_id
  left join finished f on f.order_no = n.trans_id
where
  b.order_no is null and
  p.order_no is null and
  o.order_no is null and
  f.order_no is null

简化了对多个表使用NOT IN语句的方法

3 个答案: