英文:
MongoDB filter when two fields equal
问题
{ "history_doc.data.objectId": { "$eq": "_id" } }
{ "history_doc.data.objectId": { "$eq": { "$toString": "_id" } } }
英文:
Does anyone who knows how to filter data and only keep those history_doc.data.objectId equals _id?
I have tried so many methods but none of them works
{'history_doc.data.objectId': {$eq: '$_id'}}
{'history_doc.data.objectId': {$eq: {$toString: '$_id'}}}
答案1
得分: 0
你可以在聚合查询中像这样使用 $expr 和 $eq 与 $toObjectId：
.aggregate({
$match: {
$expr: {
$eq: [
"_id",
{
"$toObjectId": "$history_doc.data.objectId"
}
]
}
}
})
示例在这里。
英文:
You can use $expr and $eq with $toObjectId into aggregation query like this:
.aggregate({
$match: {
$expr: {
$eq: [
"$_id",
{
"$toObjectId": "$history_doc.data.objectId"
}
]
}
}
})
Example here.
答案2
得分: 0
你可以使用聚合框架来完成：
$match- 根据自定义条件筛选文档$eq和$toString- 用于检查_id和history_doc.data.objectId是否相同。
db.collection.aggregate([
{
"$match": {
"$expr": {
"$eq": [
{
"$toString": "$_id"
},
"$history_doc.data.objectId"
]
}
}
}
])
英文:
You can do it with Aggregation Framework:
$match- to filter documents based on some custom criteria$eqand$toString- To check it_idandhistory_doc.data.objectIdare the same.
db.collection.aggregate([
{
"$match": {
"$expr": {
"$eq": [
{
"$toString": "$_id"
},
"$history_doc.data.objectId"
]
}
}
}
])
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