Mysql 满足某些条件时，在唯一键上合并字符串单元格

我有一个这样的结果集，但我想以某种方式合并ID列重复的行，只保留值以“Y”或“N”结尾但前面的数字大于0的单元格。 我仅通过添加

SUM

agg函数和按行的唯一标识符分组（在我的情况下是TELEFON+CULOARE列）来处理数字

此结果的查询：

ID  TELEFON     CULOARE    piesa1   piesa2  piesa3  piesa4
1   telefon1    culoare1    0N        0N      0N      0N
1   telefon1    culoare1    14Y       0N      0N      0N
2   telefon2    culoare2    0N        8Y      0N      0N
2   telefon2    culoare2    0N        0N      4Y      0N
3   telefon3    culoare3    0N        0N      0N      0Y
3   telefon3    culoare3    0N        0N      0N      0N
3   telefon3    culoare3    0N        0N      0N      0N
3   telefon3    culoare3    0N        0N      5Y      0N
4   telefon4    Neutru      8N        0N      0N      0N
4   telefon4    Neutru      0N        0N      1N      0N
4   telefon4    Neutru      0N        0N      0N      7Y

我的期望结果如下：

SELECT tt.id as `#`
,t.telefon as TELEFON
, IFNULL(c.culoare,'Neutru') as CULOARE
, (IF(p.piesa = 'piesa1', CONCAT(tt.total_piese,tt.is_stoc_min),'0N')) AS piesa1
,(IF(p.piesa = 'piesa2', CONCAT(tt.total_piese,tt.is_stoc_min),'0N')) AS piesa2
,(IF(p.piesa = 'piesa3', CONCAT(tt.total_piese,tt.is_stoc_min),'0N')) AS piesa3
,(IF(p.piesa = 'piesa4', CONCAT(tt.total_piese,tt.is_stoc_min),'0N')) AS piesa4 
,tt.total_piese
,tt.is_stoc_min
FROM telefon as t LEFT JOIN
total_piese as tt
ON t.id = tt.id_telefon
LEFT JOIN culoare as c
ON c.id  = tt.id_culoare
LEFT JOIN piesa as p
ON p.id = tt.id_piesa
ORDER BY t.id;

我有一个查询返回合并的行，但在值的末尾没有“Y”或“N”：

TELEFON     CULOARE   piesa1    piesa2  piesa3  piesa4
telefon1    culoare1    14Y       0N      0N      0N
telefon2    culoare2    0N        8Y      4Y      0N
telefon3    culoare3    0N        0N      5Y      0Y
telefon4    Neutru      8N        0N      1N      7Y

---

嗯，很难给你一个更好（或更优化）的答案，因为我们没有“基本数据”，但已经有了结果

无论如何，您可以将第一次尝试用作子查询，在piesa字段上使用

max

。（因为任何数字都将大于0，而Y大于N，因此

MAX

应提供所需的输出）

或者可能（未测试）在查询中直接使用max

select id as `#`, telefon, culoare,
max(piesa1) as piesa1,
max(piesa2) as piesa2,
max(piesa3) as piesa3,
max(piesa4) as piesa4
from
  (SELECT 
     tt.id 
    ,t.telefon as TELEFON
    ,IFNULL(c.culoare,'Neutru') as CULOARE
    ,(IF(p.piesa = 'piesa1', CONCAT(tt.total_piese,tt.is_stoc_min),'0N')) AS piesa1
    ,(IF(p.piesa = 'piesa2', CONCAT(tt.total_piese,tt.is_stoc_min),'0N')) AS piesa2
    ,(IF(p.piesa = 'piesa3', CONCAT(tt.total_piese,tt.is_stoc_min),'0N')) AS piesa3
    ,(IF(p.piesa = 'piesa4', CONCAT(tt.total_piese,tt.is_stoc_min),'0N')) AS piesa4 
    ,tt.total_piese
    ,tt.is_stoc_min
  FROM telefon as t LEFT JOIN
    total_piese as tt ON t.id = tt.id_telefon
  LEFT JOIN culoare as c ON c.id  = tt.id_culoare
  LEFT JOIN piesa as p ON p.id = tt.id_piesa) s
GROUP BY id, telefon, culoare
ORDER BY Id

---

如果我将您想要的结果更正为：第2行：

0n8y4y0n

/3行：

0n5y0y

/line4:

8n0n1n7y

是的，您是对的，根据您的评论调整了问题，感谢我现在拥有的数据，这两个查询都非常有效。将使用生产数据进行测试，如果一切正常，则标记为接受答案。谢谢，。

select id as `#`, telefon, culoare,
max(piesa1) as piesa1,
max(piesa2) as piesa2,
max(piesa3) as piesa3,
max(piesa4) as piesa4
from
  (SELECT 
     tt.id 
    ,t.telefon as TELEFON
    ,IFNULL(c.culoare,'Neutru') as CULOARE
    ,(IF(p.piesa = 'piesa1', CONCAT(tt.total_piese,tt.is_stoc_min),'0N')) AS piesa1
    ,(IF(p.piesa = 'piesa2', CONCAT(tt.total_piese,tt.is_stoc_min),'0N')) AS piesa2
    ,(IF(p.piesa = 'piesa3', CONCAT(tt.total_piese,tt.is_stoc_min),'0N')) AS piesa3
    ,(IF(p.piesa = 'piesa4', CONCAT(tt.total_piese,tt.is_stoc_min),'0N')) AS piesa4 
    ,tt.total_piese
    ,tt.is_stoc_min
  FROM telefon as t LEFT JOIN
    total_piese as tt ON t.id = tt.id_telefon
  LEFT JOIN culoare as c ON c.id  = tt.id_culoare
  LEFT JOIN piesa as p ON p.id = tt.id_piesa) s
GROUP BY id, telefon, culoare
ORDER BY Id

SELECT tt.id as `#`
,t.telefon as TELEFON
,IFNULL(c.culoare,'Neutru') as CULOARE
,max((IF(p.piesa = 'piesa1', CONCAT(tt.total_piese,tt.is_stoc_min),'0N'))) AS piesa1
,max((IF(p.piesa = 'piesa2', CONCAT(tt.total_piese,tt.is_stoc_min),'0N'))) AS piesa2
,max((IF(p.piesa = 'piesa3', CONCAT(tt.total_piese,tt.is_stoc_min),'0N'))) AS piesa3
,max((IF(p.piesa = 'piesa4', CONCAT(tt.total_piese,tt.is_stoc_min),'0N'))) AS piesa4 
FROM telefon as t LEFT JOIN
total_piese as tt
ON t.id = tt.id_telefon
LEFT JOIN culoare as c
ON c.id  = tt.id_culoare
LEFT JOIN piesa as p
ON p.id = tt.id_piesa
GROUP BY tt.Id, t.telefon, c.culoare
ORDER BY t.id;