從 MongoDB 中的巢狀 JSON 陣列中檢索值?
要從巢狀的 JSON 陣列中檢索值,可以使用以下語法 −
db.yourCollectionName.find({"yourOuterFieldName.yourInnerFieldName.yourNextInnerFieldName…...N": "yourValue"}).pretty();我們先建立一個包含文件的集合 −
> db.nestedJSONArrayDemo.insertOne({
... "ClientDetails" :
... {
... "ClientPersonalDetails" : [
... { "CountryName" : "US" },
... { "CountryName" : "AUS"},
... { "ClientName":"Chris" },
... { "ClientName":"David" }
... ]
... }
... });
{
"acknowledged" : true,
"insertedId" : ObjectId("5cd2cbb2b64f4b851c3a13bc")
}
> db.nestedJSONArrayDemo.insertOne({
... "ClientDetails" :
... {
... "ClientPersonalDetails" : [
... { "CountryName" : "Belgium" },
... { "CountryName" : "Canada"},
... { "CountryName" : "Egypt"},
... ]
... }
... });
{
"acknowledged" : true,
"insertedId" : ObjectId("5cd2cc14b64f4b851c3a13bd")
}以下是使用 find() 方法從集合中顯示所有文件的查詢 −
> db.nestedJSONArrayDemo.find().pretty();
這將生成以下輸出 −
{
"_id" : ObjectId("5cd2cbb2b64f4b851c3a13bc"),
"ClientDetails" : {
"ClientPersonalDetails" : [
{
"CountryName" : "US"
},
{
"CountryName" : "AUS"
},
{
"ClientName" : "Chris"
},
{
"ClientName" : "David"
}
]
}
}
{
"_id" : ObjectId("5cd2cc14b64f4b851c3a13bd"),
"ClientDetails" : {
"ClientPersonalDetails" : [
{
"CountryName" : "Belgium"
},
{
"CountryName" : "Canada"
},
{
"CountryName" : "Egypt"
}
]
}
}以下是從 MongoDB 中的巢狀 JSON 陣列中檢索值的查詢 −
> db.nestedJSONArrayDemo.find({"ClientDetails.ClientPersonalDetails.CountryName": "Canada"}).pretty();這將生成以下輸出 −
{
"_id" : ObjectId("5cd2cc14b64f4b851c3a13bd"),
"ClientDetails" : {
"ClientPersonalDetails" : [
{
"CountryName" : "Belgium"
},
{
"CountryName" : "Canada"
},
{
"CountryName" : "Egypt"
}
]
}
}
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