哪个MongoDB查询在数组中多次找到相同的值？
您可以将$where运算符与一些脚本一起使用。
首先让我们创建一个包含文档的集合-
> dbsameValueMultipleTimesDemoinsertOne(
{
"ListOfPrice":[
{"Price": 110},
{"Price":130},
{"Price": 145}
]
}
);
{
"acknowledged" : true,
"insertedId" : ObjectId("5cefc4e6ef71edecf6a1f6b9")
}
> dbsameValueMultipleTimesDemoinsertOne(
{
"ListOfPrice":[
{"Price": 110},
{"Price":178},
{"Price": 110}
]
}
);
{
"acknowledged" : true,
"insertedId" : ObjectId("5cefc4e7ef71edecf6a1f6ba")
}以下是在find()方法的帮助下显示集合中所有文档的查询-
> dbsameValueMultipleTimesDemofind()pretty();
输出结果
{
"_id" : ObjectId("5cefc4e6ef71edecf6a1f6b9"),
"ListOfPrice" : [
{
"Price" : 110
},
{
"Price" : 130
},
{
"Price" : 145
}
]
}
{
"_id" : ObjectId("5cefc4e7ef71edecf6a1f6ba"),
"ListOfPrice" : [
{
"Price" : 110
},
{
"Price" : 178
},
{
"Price" : 110
}
]
}以下是在数组中多次查找相同值的查询-
> dbsameValueMultipleTimesDemofind({
"$where": function() {
return thisListOfPricefilter(function(p) {
return pPrice == 110;
})length > 1;
}
})输出结果
{ "_id" : ObjectId("5cefc4e7ef71edecf6a1f6ba"), "ListOfPrice" : [ { "Price" : 110 }, { "Price" : 178 }, { "Price" : 110 } ] }