下面是数组联系人的架构。联系人数组有一个字段标签，它是另一个数组。如何从数组 Hashtags 中删除元素 openLove？
"contacts" : [
{
"addedDate" : ISODate("2015-12-02T09:06:09.891Z"),
"personEmailId" : "<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="aadecfc6c684cccbcecdcccecdeacdc7cbc3c684c9c5c7" rel="noreferrer noopener nofollow">[email protected]</a>",
"_id" : ObjectId("565eb481bf35eeb83d7f9f13"),
"verified" : true,
"favorite" : true,
"linkedinUserName" : null,
"facebookUserName" : null,
"twitterUserName" : "IamlifePaul",
"count" : 2,
"relationshipStrength_updated" : 0,
"contactRelation" : {
"decisionmaker_influencer" : null,
"prospect_customer" : "prospect"
},
"source" : "abc",
"mobileNumber" : "3546789",
"skypeId" : "123",
"designation" : "test",
"companyName" : "Something",
"location" : "Hyderabad, Telangana, India",
"personName" : "Naveen Paul",
"personId" : "565022d7dbeaeb9e17fc7083",
"hashtag" : [
"latestTag",
"anotherTag",
"#hash",
"openLove",
"hellTwo",
"working?",
"hello",
"lol",
"zxc"
],
"lastInteracted" : ISODate("2015-12-08T05:07:53.746Z")
},
{
"addedDate" : ISODate("2015-12-02T09:06:09.891Z"),
"personEmailId" : "<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="d1bfb0a7b4b4bfa1b0a4bdffb7b0b5b6b7b5b691b6bcb0b8bdffb2bebc" rel="noreferrer noopener nofollow">[email protected]</a>",
"_id" : ObjectId("565eb481bf35eeb83d7f9f13"),
"verified" : true,
"favorite" : true,
"linkedinUserName" : null,
"facebookUserName" : null,
"twitterUserName" : "IamlifePaul",
"count" : 2,
"relationshipStrength_updated" : 0,
"contactRelation" : {
"decisionmaker_influencer" : null,
"prospect_customer" : "prospect"
},
"source" : "abc",
"mobileNumber" : "3546789",
"skypeId" : "123",
"designation" : "test",
"companyName" : "Something",
"location" : "Hyderabad, Telangana, India",
"personName" : "Naveen Paul",
"personId" : "565022d7dbeaeb9e17fc7083",
"hashtag" : [
"latestTag",
"anotherTag",
"#hash",
"openLove",
"hellTwo",
"working?",
"hello",
"lol",
"zxc"
],
"lastInteracted" : ISODate("2015-12-08T05:07:53.746Z")
},
{
"addedDate" : ISODate("2015-12-02T09:06:09.891Z"),
"personEmailId" : "<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="761817001313180617031a581017121110121136111b171f1a5815191b" rel="noreferrer noopener nofollow">[email protected]</a>",
"_id" : ObjectId("565eb481bf35eeb83d7f9f13"),
"verified" : true,
"favorite" : true,
"linkedinUserName" : null,
"facebookUserName" : null,
"twitterUserName" : "IamlifePaul",
"count" : 2,
"relationshipStrength_updated" : 0,
"contactRelation" : {
"decisionmaker_influencer" : null,
"prospect_customer" : "prospect"
},
"source" : "abc",
"mobileNumber" : "3546789",
"skypeId" : "123",
"designation" : "test",
"companyName" : "Something",
"location" : "Hyderabad, Telangana, India",
"personName" : "Naveen Paul",
"personId" : "565022d7dbeaeb9e17fc7083",
"hashtag" : [
"polly",
"tagger",
"#hash",
"working?",
"hello",
"lol",
"zxc"
],
"lastInteracted" : ISODate("2015-12-08T05:07:53.746Z")
}
如何从数组标签中删除元素？ 例如删除openLove？
最佳答案
您通常会使用 positional operator $ 来执行此操作如下:
db.collection.update(
{ "contacts.hashtag": "openLove" },
{
"$pull": {
"contacts.$.hashtag": "openLove"
}
}
)
但是，由于这仅支持单级深度数组(位置 $ operator 充当与查询文档匹配的第一个元素的占位符)，因此仅支持与查询匹配的第一个元素文档被删除。这里有一个可追踪的 JIRA:https://jira.mongodb.org/browse/SERVER-831
如果您事先知道包含要删除的元素的主题标签数组的索引，则更新查询将为:
db.collection.update(
{ "contacts.hashtag": "openLove" },
{
"$pull": {
"contacts.0.hashtag": "openLove",
"contacts.1.hashtag": "openLove"
}
}
)
考虑重新设计您的架构以避免嵌套数组，以便您可以通过创建单独的联系人集合来标准化您的集合，其中每个文档代表一个联系人，并包含原始集合中重复的一组联系人的通用信息。类似于以下内容:
集合架构:
{
_id: collection_id,
contacts: [
ObjectId("565eb481bf35eeb83d7f9f13"),
ObjectId("565eb481bf35eeb83d7f9f14"),
ObjectId("565eb481bf35eeb83d7f9f15")
]
}
联系人架构:
{
"addedDate" : ISODate("2015-12-02T09:06:09.891Z"),
"personEmailId" : "<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="ff8b9a9393d1999e9b98999b98bf98929e9693d19c9092" rel="noreferrer noopener nofollow">[email protected]</a>",
"_id" : ObjectId("565eb481bf35eeb83d7f9f13"),
...
"hashtag" : [
"latestTag",
"anotherTag",
"#hash",
"openLove",
"hellTwo",
"working?",
"hello",
"lol",
"zxc"
],
"lastInteracted" : ISODate("2015-12-08T05:07:53.746Z")
},
{
"addedDate" : ISODate("2015-12-02T09:06:09.891Z"),
"personEmailId" : "<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="ed838c9b8888839d8c9881c38b8c898a8b898aad8a808c8481c38e8280" rel="noreferrer noopener nofollow">[email protected]</a>",
"_id" : ObjectId("565eb481bf35eeb83d7f9f14"),
...
"hashtag" : [
"latestTag",
"anotherTag",
"#hash",
"openLove",
"hellTwo",
"working?",
"hello",
"lol",
"zxc"
],
"lastInteracted" : ISODate("2015-12-08T05:07:53.746Z")
},
{
"addedDate" : ISODate("2015-12-02T09:06:09.891Z"),
"personEmailId" : "<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="d5bbb4a3b0b0bba5b4a0b9fbb0b0a2a6b1b395b2b8b4bcb9fbb6bab8" rel="noreferrer noopener nofollow">[email protected]</a>",
"_id" : ObjectId("565eb481bf35eeb83d7f9f15"),
...
"hashtag" : [
"polly",
"tagger",
"#hash",
"working?",
"hello",
"lol",
"zxc"
],
"lastInteracted" : ISODate("2015-12-08T05:07:53.746Z")
}
更新联系人集合会更容易，只需运行该操作
db.contacts.update(
{ "hashtag": "openLove" },
{
"$pull": { "hashtag": "openLove" }
}
)
如果重新设计架构超出了您的范围，那么您将需要一种机制来动态生成更新文档，即创建 $pull 动态对象。考虑使用 Map-Reduce 来生成这个 answer 详细介绍了整个运营理念。
关于arrays - 从 MongoDb 中的数组的数组中删除元素，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/34507696/