Couchbase SQL++中含CASE语句的Left Join查询表现为Inner Join的问题求助

大家好，我最近在用Couchbase SQL++写查询时碰到了一个棘手的问题：原本想通过Left Join保留左表的全部数据，但加入CASE语句后，查询结果却只返回了有匹配关联数据的行，完全变成了Inner Join的效果，实在搞不懂哪里出问题了。

先给大家看一下我的基础查询，这个查询能正常返回9行符合条件的数据：

SELECT i.id, i.docId, i.proId, i.invRecipientType
FROM pulse i
WHERE i.type = 'pulseInvoice'
  AND i.invRecipientType IN ['cpam', 'b2b', 'b2c']
  AND i.orgId = 'pulseOrganization::S00001'
  AND i.ageId = 'pulseAgency::S00001'
  AND i.invStatus IN ['pending', 'error']
  AND i.sysActive = true
  AND i.invRecordingDate >= '2024-06-01' 
  AND i.invRecordingDate <= '2024-06-07'

返回的结果示例（共9行）：

[
  {
    "id": "pulseInvoice::isl98829abd50231111efa73e4311e980c8e3",
    "docId": null,
    "proId": null,
    "invRecipientType": "b2c"
  },
  {
    "id": "pulseInvoice::enugl9e03791024ab11efa035dffe4b27df14",
    "docId": "pulseDoctor::FRMS10002116811",
    "proId": null,
    "invRecipientType": "cpam"
  },
  {
    "id": "pulseInvoice::z0rty6df5e850f58211eeac6b8d2531aa0da6",
    "docId": ...
  },
  // 剩余6行结果省略
]

接下来我想关联另外两个表，根据invRecipientType的不同，用CASE语句返回对应的接收方名称，于是写了下面这个带Left Join和CASE的查询：

SELECT 
  i.id, 
  i.docId, 
  i.proId, 
  i.invRecipientType,
  CASE 
    WHEN i.invRecipientType = 'cpam' THEN d.doctorName
    WHEN i.invRecipientType = 'b2b' THEN c.companyName
    ELSE NULL
  END AS recipientName
FROM pulse i
LEFT JOIN doctors d ON i.docId = d.id AND i.invRecipientType = 'cpam'
LEFT JOIN companies c ON i.proId = c.id AND i.invRecipientType = 'b2b'
WHERE i.type = 'pulseInvoice'
  AND i.invRecipientType IN ['cpam', 'b2b', 'b2c']
  AND i.orgId = 'pulseOrganization::S00001'
  AND i.ageId = 'pulseAgency::S00001'
  AND i.invStatus IN ['pending', 'error']
  AND i.sysActive = true
  AND i.invRecordingDate >= '2024-06-01' 
  AND i.invRecordingDate <= '2024-06-07'

按道理Left Join应该保留左表pulse的所有9行数据，没有匹配关联的行里recipientName显示NULL就好，但实际结果却只返回了3行——只有invRecipientType为cpam且能匹配到doctors表、或者为b2b且能匹配到companies表的行，那些b2c的行直接被过滤掉了，完全是Inner Join的表现。

我反复检查了Join的条件和CASE语句，没发现明显错误，有没有大佬遇到过类似的情况？或者Couchbase SQL++在处理CASE和Left Join结合时有什么特殊的规则？麻烦帮忙指点一下，谢谢！

备注：内容来源于stack exchange，提问作者Gnujeremie