列作為子查詢

Question

需要有一個第3列，它將對每個第1列（單詞）的所有點求和，但是它將對每行的'％word％'之類的所有單詞的點進行求和，例如'chef'這個單詞將具有'廚師'和'廚師廚師'等點

SELECT word, SUM(points) as points  
  FROM table
group by word

Answer 1

你可以測試一下。 然而，加入LIKE並不是很有效。

;WITH Words AS(
    SELECT word ,sum(points) as points, 
    FROM table group by word
)

SELECT
    W.word,
    W.points,
    LikeWordPoints = W.points + ISNULL(SUM(LikeWord.points),0)
FROM
    Words W
    LEFT OUTER JOIN Words LikeWord ON LikeWord.word LIKE '%'+W.word+'%' AND LikeWord.word <> W.word
GROUP BY
    W.word,
    W.points

Answer 2

如果我理解正確，我可能會使用correlated subquery ：

select distinct w.word, 
      (select sum(points) from words w2 where w2.word like '%' + w.word + '%') as points
from words w

• 在線演示

Answer 3

選擇中的相關子查詢可能會降低性能。 我建議使用加入或交叉申請

select distinct w.word, C.SumOfPoints as sumofpoints
from words w
CROSS APPLY (SELECT SUM(points) AS SumOfPoints from words w2 WHERE w2.word like '%' + 
w.word + '%') C