从MongoDB中的嵌套JSON数组中检索值？
要从嵌套的JSON数组中检索值，可以使用以下语法-
db.yourCollectionName.find({"yourOuterFieldName.yourInnerFieldName.yourNextInnerFieldName…...N": "yourValue"}).pretty();首先让我们创建一个包含文档的集合-
> 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")
}以下是在find()方法的帮助下显示集合中所有文档的查询-
> db.nestedJSONArrayDemo.find().pretty();
这将产生以下输出-
{
"_id" : ObjectId("5cd2cbb2b64f4b851c3a13bc"),
"ClientDetails" : {
"ClientPersonalDetails" : [
{
"CountryName" : "US"
},
{
"CountryName" : "AUS"
},
{
"ClientName" : "Chris"
},
{
"ClientName" : "David"
}
]
}
}
{
"_id" : ObjectId("5cd2cc14b64f4b851c3a13bd"),
"ClientDetails" : {
"ClientPersonalDetails" : [
{
"CountryName" : "Belgium"
},
{
"CountryName" : "Canada"
},
{
"CountryName" : "Egypt"
}
]
}
}以下是从MongoDB中的嵌套JSON数组检索值的查询-
> db.nestedJSONArrayDemo.find({"ClientDetails.ClientPersonalDetails.CountryName": "Canada"}).pretty();这将产生以下输出-
{
"_id" : ObjectId("5cd2cc14b64f4b851c3a13bd"),
"ClientDetails" : {
"ClientPersonalDetails" : [
{
"CountryName" : "Belgium"
},
{
"CountryName" : "Canada"
},
{
"CountryName" : "Egypt"
}
]
}
}