我正在尝试编写一个查询，我可以根据DB2 v9.5中case语句的结果将某些行连接成一个列
contractId也可以是可变数量的行。
鉴于我有以下表结构
Table1
+------------+------------+------+
| ContractId | Reference | Code |
+------------+------------+------+
| 12 | P123456789 | A |
| 12 | A987654321 | B |
| 12 | 9995559971 | C |
| 12 | 3215654778 | D |
| 13 | abcdef | A |
| 15 | asdfa | B |
| 37 | 282jd | B |
| 89 | asdf82 | C |
+------------+------------+------+
我想得到结果的输出
+-------------+-----------------------+------------------------------------+
| ContractId | Reference with Code A | Other References |
+-------------+-----------------------+------------------------------------+
| 12 | P123456789 | A987654321, 9995559971, 3215654778 |
| 13 | abcdef | asdfa, 282jd, asdf82 |
+-------------+-----------------------+------------------------------------+
我尝试了像
这样的查询select t1.contract_id,
max(case when t1.code = A then t1.reference end) as "reference with code a",
max(case when t1.code in ('B','C','D') then t1.reference end) as 'other references
from table t1
group by t1.contractId
然而，这仍然给我一个像
这样的输出+-------------+-----------------------+------------------+
| ContractId | Reference with Code A | Other References |
+-------------+-----------------------+------------------+
| 12 | P123456789 | null |
| 12 | null | A987654321 |
| 12 | null | 9995559971 |
| 12 | null | 3215654778 |
+-------------+-----------------------+------------------+
我也尝试过使用一些XML Agg函数，但似乎无法按照我想要的方式进行格式化。