Question

假设我有一个名为“records”的数据库表，它有三个实体“id”，“name”，“score”。

如果有重复的值，如;

id  name  score
1   ben   10
2   adam   4
3   sarah  2
4   ben    5
5   mark   3

由于有两个benı可以使用此sql语句删除其中一个

DELETE FROM records
WHERE id IN
( SELECT MAX(id) FROM records
GROUP BY name
HAVING COUNT(*) > 1)

但是我怎样才能将ben的值加到其他ben上并得到类似的东西;

id  name  score
1   ben    15
2   adam   4
3   sarah  2
5   mark   3

Answer 1

SELECT Min(id) as id ,name,SUM(score) as score FROM records
GROUP BY name

Answer 2

尝试以下查询：

select id,name,sum(score) over (partition by name) score
into #t1
from test3
order by id

DELETE FROM #t1
WHERE id IN
(SELECT MAX(id) FROM #t1
GROUP BY name
HAVING COUNT(*) > 1)

select * from #t1
order by id

drop table #t1

Answer 3

您可以使用：

-- get min(id) and total
SELECT id = MIN(id),name, total = SUM(score)
INTO #temp
FROM records
GROUP BY name;

-- update score
UPDATE r
SET score = total
FROM records r
JOIN #temp t
  ON r.name = t.name;

-- delete redundant rows
DELETE r
FROM records r
LEFT JOIN #temp t
 ON r.id = t.id
WHERE t.id IS NULL;

SELECT * FROM records;

的 LiveDemo

使用MERGE：

MERGE records AS tgt USING (SELECT id = MIN(id),name, total = SUM(score) FROM records GROUP BY name) AS src ON tgt.name = src.name WHEN MATCHED AND tgt.id <> src.id THEN DELETE WHEN MATCHED THEN UPDATE SET score = total;

的 LiveDemo2

输出：

╔════╦═══════╦═══════╗ ║ id ║ name ║ score ║ ╠════╬═══════╬═══════╣ ║ 1 ║ ben ║ 15 ║ ║ 2 ║ adam ║ 4 ║ ║ 3 ║ sarah ║ 2 ║ ║ 5 ║ mark ║ 3 ║ ╚════╩═══════╩═══════╝

Answer 4

使用此查询：

--This will delete all duplicate records except their first occurrence. You may ignore this part if you do not need to delete
DELETE FROM T 
WHERE Id IN (
             SELECT Id FROM(
                            --This select will produce the result that you are looking for
                            SELECT Id, 
                                   name, 
                                   SUM(Score)OVER(PARTITION BY name) AS S,
                                   ROW_NUMBER()OVER(PARTITION BY name ORDER BY Id ) AS RN
                            FROM T
                           ) AS K WHERE RN>1
             )

如何删除重复数据并在sql上求和它的值？

4 个答案: