sql内连接单表

Posted 2023-03-24

【中文标题】sql内连接单表

【英文标题】：sql inner join single table

【发布时间】：2016-01-25 19:35:20

【问题描述】：

三列表格； ID、术语、同义词

1, IDENTITY, CHARACTER
2, IDENTITY, EXISTENCE
3, IDENTITY, IDENTIFICATION
4, IDENTITY, INTEGRITY 
5, IDENTITY, NAME
6, CIRCUMSTANCES, ASSETS
7, CIRCUMSTANCES, CAPITAL
8, CIRCUMSTANCES, CHANCES

我需要结果返回具有关联“同义词”的不同“术语”，消除多对多并返回一对多作为结果。

1, IDENTITY, CHARACTER | EXISTENCE | IDENTIFICATION | INTEGRITY | NAME
6, CIRCUMSTANCES, ASSETS |CAPITAL | CHANCES

或者，

1、TERM="IDENTITY" SYNONYM="CHARACTER" SYNONYM="EXISTENCE" SYNONYM="IDENTIFICATION" SYNONYM="INTEGRITY" SYNONYM="NAME"

2、TERM="CIRCUMSTANCES" SYNONYM="ASSETS" SYNONYM="CAPITAL" SYNONYM="CHANCES"

【问题讨论】：

请澄清您的问题。

***.com/help/how-to-ask

【参考方案1】：

如果你使用 mysql，可以使用GROUP_CONCAT

SELECT MIN(`ID`), `TERM`, GROUP_CONCAT(`SYNONYM`, ' | ') 
FROM my_table
GROUP BY `TERM`;

【讨论】：

感谢您的帖子。GROUP_CONCAT 无法识别

【参考方案2】：

Oracle 解决方案 - 从 11g 开始：

with sample as
(
  select 1 ID,  'IDENTITY' term , 'CHARACTER' syn from dual
  union all
  select 2, 'IDENTITY', 'EXISTENCE' from dual 
  union all
  select 3, 'IDENTITY', 'IDENTIFICATION' from dual 
  union all
  select 4, 'IDENTITY', 'INTEGRITY' from dual 
  union all
  select 5, 'IDENTITY', 'NAME' from dual 
  union all
  select 6, 'CIRCUMSTANCES', 'ASSETS' from dual 
  union all
  select 7, 'CIRCUMSTANCES', 'CAPITAL' from dual 
  union all
  select 8, 'CIRCUMSTANCES', 'CHANCES' from dual 
)
select  min(id) id, term,
listagg(syn,'|') within group(order by syn) syns
from sample
group by term;

输出：

      ID TERM          SYNS
---------- ------------- ------------------------------------------------------
         6 CIRCUMSTANCES ASSETS|CAPITAL|CHANCES
         1 IDENTITY      CHARACTER|EXISTENCE|IDENTIFICATION|INTEGRITY|NAME

【讨论】：

它与 DB2 相悖，不喜欢 WITHIN，但我现在有一张很好的图片，并且会解决它。谢谢！