Question

mysql：

SELECT * 
FROM (select * from songs order by artist asc) as songs2 
WHERE artist LIKE 'a%' GROUP BY artist`

mssql：

SELECT * 
FROM (select top 1000 * from songs order by artist asc) as songs2  
WHERE artist LIKE 'a%' GROUP BY artist

这适用于mysql但在mssql中我收到错误：

列'songs2.id'在选择列表中无效，因为它不是包含在聚合函数或GROUP BY子句
中

++++++++++++++++++ 现在我选择这个查询：选择艺术家，专辑，歌曲（从歌曲顺序选择前1000名* asc，艺术家asc）作为歌曲2，其中艺术家喜欢'a％'按艺术家，专辑，歌曲分组; 但它不按艺术家分组，我希望查询中每首歌只有一位艺术家

Answer 1

在mysql中，您可以选择不在group by语句中的值。这在mssql中是不可能的。

SELECT artist FROM 
(
    select * from songs 
) as songs2 
where artist like 'a%' group by artist;

而且你也不能在子查询中使用order by。

Answer 2

删除ORDER BY子句：

SELECT * FROM 
(
    select * from songs 
) as songs2 
where artist like 'a%';

没有必要订购sub-query中的行，因为您没有使用TOP来获取N，OFFSET来应用分页或{{1订购FOR XML个节点。

如果您想订购结果，请在外部查询中执行：

XML

所以，基本上，你可以缩短这个：

SELECT * FROM 
(
    select * from songs 
) as songs2 
where artist like 'a%'
order by year asc, artist asc;

Answer 3

在子查询中排序需要 TOP / OFFSET / FOR XML Cluase

SELECT artist FROM 
(
    select top 100 percent * from songs 
    order by year asc, artist asc
) as songs2 
where artist like 'a%' group by artist;

Answer 4

这将为每位艺术家找到1首歌曲，最多可以找到1000首歌曲：

SELECT TOP 1000 
  artist,album,song 
FROM 
(
  SELECT 
    artist,album,song, 
    row_number() over (partition by artist order by (SELECT 1)) rn
  FROM table_name 
  WHERE artist like 'a%' 
) as t2 
WHERE rn = 1

这个SQL查询在mysql中工作，但在mssql中不起作用

4 个答案: