1
我有以下数据:如何查询MongoDB中的空文档子集合?
/* 1 */
{
"_id" : 1,
"FirstName" : "John",
"LastName" : "Doe",
"Test" : [{
"TestId" : ObjectId("5046109daedabb0cf8800f3f"),
"DateTaken" : ISODate("2012-09-10T15:46:32.866Z")
}, {
"TestId" : ObjectId("506e0928aedabb087c4ec9d1"),
"DateTaken" : ISODate("2011-06-26T18:05:52.625Z"),
"Responses" : [{
"AnswerId" : "506e0928aedabb087c4ec98c",
"QuestionId" : ObjectId("506e0928aedabb087c4ec98b"),
"ResponseDate" : ISODate("2011-06-26T04:00:00Z")
}]
}]
}
/* 2 */
{
"_id" : 2,
"FirstName" : "Jane",
"LastName" : "Doe",
"TestHistory" : [{
"TestId" : ObjectId("506e0928aedabb087c4ec9d1"),
"DateTaken" : ISODate("2011-06-26T18:05:52.625Z"),
"Responses" : [{
"AnswerId" : "506e0928aedabb087c4ec98c",
"QuestionId" : ObjectId("506e0928aedabb087c4ec98b"),
"ResponseDate" : ISODate("2011-06-26T04:00:00Z")
}]
}]
}
我试图写一个返回在存在测试有没有回应所有实例的查询。我曾尝试以下查询:
- { “Test.Responses”:{$存在:假}}
- {$和:[{测试:{$退出:真}},{“ Test.Responses“:{$存在:假}}]}
这两者返回0的结果。我错过了什么?
可能的重复http://stackoverflow.com/questions/6607102/mongodb-match-non-empty-doc-in-array。请参阅http://stackoverflow.com/questions/6607102/mongodb-match-non-empty-doc-in-array#comment18700846_6838057 – 2013-03-05 19:06:42
中的注释,与测试字段的非空值不同,“$ size”不使用索引 – Sammaye 2013-03-05 19:23:20