将 native Nodejs 驱动程序与 MongoDB 2.4 结合使用，并尝试从数组中嵌入的文档中删除属性。例如。如何从 grades 数组中嵌入的文档中删除 gym 属性，其中 gym 为 562e7c1ae6c3e8ce29abfe05？所以由此而来:
{
"_id" : ObjectId("562abaaffb5870b8fb9dca3f"),
"grades" : [
{
"_id" : ObjectId("562e7bbe70ee82bb290192bd"),
"discipline" : "55aae5b7848b9c8bf4ecbb5c",
"grade" : "55aae5b7848b9c8bf4ecbb4c",
"gym" : "562e7c1ae6c3e8ce29abfe06",
"registeredOn" : ISODate("2015-10-26T19:15:10.565Z")
},
{
"discipline" : "55aae5b7848b9c8bf4ecbb5c",
"grade" : "55aae5b7848b9c8bf4ecbb4d",
"gym" : "562e7c1ae6c3e8ce29abfe05",
"registeredOn" : ISODate("2015-10-26T19:17:08.603Z"),
"_id" : ObjectId("562e7c34e6c3e8ce29abfe06")
}
],
},
{
"_id" : ObjectId("562abaaffb5870b8fb9dca3f"),
"grades" : [
{
"_id" : ObjectId("562e7bbe70ee82bb290192bd"),
"discipline" : "55aae5b7848b9c8bf4ecbb5c",
"grade" : "55aae5b7848b9c8bf4ecbb4c",
"gym" : "562e7c1ae6c3e8ce29abfe07",
"registeredOn" : ISODate("2015-10-26T19:15:10.565Z")
},
{
"discipline" : "55aae5b7848b9c8bf4ecbb5c",
"grade" : "55aae5b7848b9c8bf4ecbb4d",
"gym" : "562e7c1ae6c3e8ce29abfe05",
"registeredOn" : ISODate("2015-10-26T19:17:08.603Z"),
"_id" : ObjectId("562e7c34e6c3e8ce29abfe06")
}
],
}
我需要这个:
{
"_id" : ObjectId("562abaaffb5870b8fb9dca3f"),
"grades" : [
{
"_id" : ObjectId("562e7bbe70ee82bb290192bd"),
"discipline" : "55aae5b7848b9c8bf4ecbb5c",
"grade" : "55aae5b7848b9c8bf4ecbb4c",
"gym" : "562e7c1ae6c3e8ce29abfe06",
"registeredOn" : ISODate("2015-10-26T19:15:10.565Z")
},
{
"discipline" : "55aae5b7848b9c8bf4ecbb5c",
"grade" : "55aae5b7848b9c8bf4ecbb4d",
"registeredOn" : ISODate("2015-10-26T19:17:08.603Z"),
"_id" : ObjectId("562e7c34e6c3e8ce29abfe06")
}
],
},
{
"_id" : ObjectId("562abaaffb5870b8fb9dca3f"),
"grades" : [
{
"_id" : ObjectId("562e7bbe70ee82bb290192bd"),
"discipline" : "55aae5b7848b9c8bf4ecbb5c",
"grade" : "55aae5b7848b9c8bf4ecbb4c",
"gym" : "562e7c1ae6c3e8ce29abfe07",
"registeredOn" : ISODate("2015-10-26T19:15:10.565Z")
},
{
"discipline" : "55aae5b7848b9c8bf4ecbb5c",
"grade" : "55aae5b7848b9c8bf4ecbb4d",
"registeredOn" : ISODate("2015-10-26T19:17:08.603Z"),
"_id" : ObjectId("562e7c34e6c3e8ce29abfe06")
}
],
}
似乎没有任何效果，而且最接近我需要的是:
collections.users.update({
"grades.gym": {
$exists: true
}
}, {
$unset: {
"grades.$.gym": "562e7c1ae6c3e8ce29abfe05"
}
}, {
multi: true
})
最佳答案
只需指向嵌入文档字段作为更新查询:
db.users.update(
{
"grades.gym": "562e7c1ae6c3e8ce29abfe05"
},
{
"$unset": {
"grades.$.gym": "562e7c1ae6c3e8ce29abfe05"
}
}, { "multi": true }
)
关于javascript - 如何使用 MongoDB 从嵌入数组的文档中删除属性？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/33354195/