Question

我想这是一个很长的镜头但是，有没有办法列出sql查询而不进行排序......

例如。我有

select * from items 
where manufacID = 2 
or manufacID = 1
or manufacID = 4

并且我不希望它们以asc或decs顺序列出，但是当我输入时......所以2,1,4。

那么，我可以这样做吗？

Answer 1

您可以在select中添加一个额外的列作为排序列，然后按顺序排序：

SELECT 
  *,
  CASE manufacID
    WHEN 2 THEN 1
    WHEN 1 THEN 2
    WHEN 4 THEN 3
  END AS sortOrder
FROM
  items
ORDER BY
  sortOrder

Answer 2

是的，请使用：

SELECT * FROM items
WHERE manufacID IN (2, 1, 4)
ORDER BY (manufacID = 2) ASC,
         (manufacID = 1) ASC,
         (manufacID = 4) ASC

结果按条件匹配的顺序排序。将ASC更改为DESC以反转顺序。这仅适用于允许sort子句中的条件的数据库。

（旁注：你为什么要这样做？）

Answer 3

由于您尚未指定排序，因此记录将按自然顺序排序，这取决于您使用的RDBMS。例如，在SQL Server中，订单未定义。

您可以通过以下值创建值来订购：

select * from items 
where manufacID in (2, 1, 4)
order by case manufacID
  when 2 then 1
  when 1 then 2
  when 4 then 3
end

Answer 4

SELECT * FROM
(
select 1 as sort, * from items 
where manufacID = 2 

union all

select 2 as sort, * from items 
where manufacID = 1

union all

select 3 as sort, * from items 
where manufacID = 4
)
order by sort

Answer 5

select * from items where manufacID = 2 
union all
select * from items where manufacID = 1
union all
select * from items where manufacID = 4

sql选择没有排序

5 个答案: