Join Couchdb参考文件

我是CouchDB的新手，正在努力实现一个基本示例。我有三个文档客户、联系人、地址，我想将它们合并到一个文档中

会计凭证

{
   "_id": "CST-1",
   "_rev": "8-089da95f148b446bd3b33a3182de709f",
   "name": "Customer",
   "code": "CST-001",
   "contact_Key": "CNT-001",
   "address_Key": "ADD-001",
   "type": "Customer"
}

   {
       "_id": "CNT-001",
       "_rev": "8-079da95f148b446bd3b33a3182de709g",
       "fullname": "Happy Swan",
       "type": "Contact"
    }

联系文件

{
   "_id": "CST-1",
   "_rev": "8-089da95f148b446bd3b33a3182de709f",
   "name": "Customer",
   "code": "CST-001",
   "contact_Key": "CNT-001",
   "address_Key": "ADD-001",
   "type": "Customer"
}

   {
       "_id": "CNT-001",
       "_rev": "8-079da95f148b446bd3b33a3182de709g",
       "fullname": "Happy Swan",
       "type": "Contact"
    }

地址文件

   {
       "_id": "ADD-001",
       "_rev": "8-179da95f148b446bd3b33a3182de709c",
       "street1": "9 Glass View",
       "street2": "Street 2",
       "city": "USA",
       "type": "Address"
    } 

地图/查询：

 var map=  function (doc) {
      if (doc.type === 'Customer') {
        emit(doc.id, { contact_Key: doc.contact_Key, address_Key: doc.address_Key })
       }
   };

 db.query({ map: map }, { include_docs: true }, function (err, res) {

 });

当我查询帐户时，我希望所有3个文档都在一个文档中，例如

预期结果

{
       "_id": "CST-1",
       "_rev": "8-089da95f148b446bd3b33a3182de709f",
       "name": "Customer",
       "code": "CST-001",
       "contact_Key": "CNT-001",
       "address_Key": "ADD-001",
       "type": "Customer",
       "Contact: {
                  "_id": "CNT-001",
                  "_rev": "8-079da95f148b446bd3b33a3182de709g",
                  "fullname": "Happy Swan",
                  "type": "Contact"
        }",
      "Address: {
           "_id": "ADD-001",
           "_rev": "8-179da95f148b446bd3b33a3182de709c",
           "street1": "9 Glass View",
           "street2": "Street 2",
           "city": "USA",
           "type": "Address"
        }"

    }

---

我认为没有比先查询帐户文档，然后在知道其他两个帐户的ID后再查询它们更好的解决方案了。如果您仔细想想，这是有意义的，因为这些文档之间的唯一链接是存储在account文档中的ID，因此要同时获取这三个ID，DB必须在内部执行两个查询：首先是account文档，然后是其他两个查询。按照设计，CouchDB一次只执行一个查询

但是，如果您将帐户文档ID存储在联系人和地址文档中，则可以使用将它们合并为一个

首先，您需要一个视图：

function(doc) {
  if (doc.type === 'Customer') {
    emit(doc._id, doc);
  }
  if (doc.type === 'Contact' || doc.type === 'Address') {
    emit(doc.account_id, doc);
  }
}

然后是一个列表函数：

function(head, req) {
  var row, account, contact, address;
  while (row = getRow()) {
    if (row.value.type === 'Customer') {
      account = row.value;
    } else if (row.value.type === 'Contact') {
      contact = row.value;
    } else if (row.value.type === 'Address') {
      address = row.value;
    }
  }
  account['Contact'] = contact;
  account['Address'] = address;
  provides("json", function() {
    return { 'json': account };
  });
}

您可以通过以下方式查询：

GET /db/_design/foo/_list/the-list/the-view?key="CST-1"

---

您是否正在尝试将所有3个文档合并到map/reduce中？文档之间有什么链接？联系人密钥和联系人id不匹配。另外，你的地图功能只发送客户文档。嗨，伙计，我已经修复了id，是的，我想加入mal/reduce，但不知道如何获得结果。谢谢Simon，你的两个建议都很好。