计算SQL中的投票数并按降序排序

Question

我在SQL中有这个包含膳食投票的表。

表：

现在，我想做的是相互计算所有相同的MealId，并按降序排序。

例如（Id | MealId | UserId | VoteDate）：

1 | 13 | 1 | somedate

2 | 1  | 2 | somedate

3 | 3  | 1 | somedate

4 | 13 | 3 | somedate

现在，在计算之后它应该是这样的：

2  //Here are the MealId's that are equal to 13
1  //Here are the MealId's that are equal to 1 or 3, because there is only 1 vote for that Meal
1  //Here are the MealId's that are equal to 1 or 3, because there is only 1 vote for that Meal

注意：它不必显示投票数：“2,1,1”，我只想按降序排序。包含大部分选票的膳食应该在最重要的位置。

Answer 1

使用窗口聚合（COUNT）将计数数据与其余数据一起放入行中，然后只需一个简单的ORDER BY：

;With TotalVotes as (
    select *,COUNT(*) OVER (PARTITION BY MealId) as Cnt
    from UnnamedTable
)
select * from TotalVotes ORDER BY Cnt desc,MealId