LISTAGG查询"ORA-00937:不是单组组功能"

Question

我正在尝试使用逗号分隔值列表创建连接.例如:

rule_id | attribute_id
----------------------
1       | a
1       | b
2       | c
2       | d

应该:

rule_id | attribute_id
----------------------
1       | a,b
2       | c,d

我试图这样做LISTAGG.但是,使用下面的代码,我得到了ORA-00937: not a single-group group function.我注意到FOR PATHsql-server 的语法,但它看起来不适用于我们的配置.这是我的查询:

SELECT r.rule_id as RULE_ID, 
LISTAGG(a.ATTRIBUTE_ID, ', ') WITHIN GROUP (ORDER BY a.ATTRIBUTE_ID) "ATTR_IDS"
FROM N_RULE r, N_ATTRIBUTE a 
WHERE r.RULE_ID = a.RULE_ID 
ORDER BY r.AUDIENCE, UPPER(r.NAME);

Answer 1

我认为你的查询工作,你需要添加一个group by,更改order by.您还应该使用正确的显式连接语法:

SELECT r.rule_id as RULE_ID, 
       LISTAGG(a.ATTRIBUTE_ID, ', ') WITHIN GROUP (ORDER BY a.ATTRIBUTE_ID) as "ATTR_IDS"
FROM N_RULE r JOIN
     N_ATTRIBUTE a 
     ON r.RULE_ID = a.RULE_ID 
GROUP BY r.rule_id
ORDER BY r.rule_id;

或者,您可能希望在结果中包含其他属性:

SELECT r.rule_id, r.AUDIENCE, UPPER(r.NAME) 
       LISTAGG(a.ATTRIBUTE_ID, ', ') WITHIN GROUP (ORDER BY a.ATTRIBUTE_ID) as "ATTR_IDS"
FROM N_RULE r JOIN
     N_ATTRIBUTE a 
     ON r.RULE_ID = a.RULE_ID 
GROUP BY r.rule_id, r.AUDIENCE, UPPER(r.NAME)
ORDER BY r.AUDIENCE, UPPER(r.NAME);