使用MongoDB取消键和值的event_params

如何解决使用MongoDB取消键和值的event_params

在Google大查询中，您可以执行嵌套（键和值）event_params，我从Big-Query获取所有Google事件并将其插入MongoDB

如何从MongoDB中选择event_params.key =“ firebase_screen_class”具有值。string_value=“ ForceUpdateVC”

我不需要获取任何event_params.value.string_value =“ ForceUpdateVC”，如果event_params.key =“ firebase_screen_class”，我仅需要此值

请帮助

[
{
    "_id" : ObjectId("5fa979330af533408048d646"),"event_name" : "screen_view","event_params" : [ 
        {
            "key" : "ga_session_id","value" : {
                "string_value" : null,"int_value" : 1604843171,"float_value" : null,"double_value" : null
            }
        },{
            "key" : "firebase_prevIoUs_class","value" : {
                "string_value" : "TrendsScreen","int_value" : null,{
            "key" : "firebase_screen_class","value" : {
                "string_value" : "ForceUpdateVC",{
            "key" : "firebase_screen_id","int_value" : NumberLong(4208934242551216926),{
            "key" : "firebase_prevIoUs_id","int_value" : NumberLong(4208934242551216925),{
            "key" : "firebase_event_origin","value" : {
                "string_value" : "auto",{
            "key" : "ga_session_number","int_value" : 49,"double_value" : null
            }
        }
    ],"updated_at" : ISODate("2020-11-09T17:15:31.021Z"),"created_at" : ISODate("2020-11-09T17:15:31.021Z")
},.
.
.
]

解决方法

您需要在event_params数组上使用$ elemMatch函数。它与javascript中array.prototype中的some（）函数相同。 您的查询将如下所示： db.collection.find（{“ event_params”：{“ $ elemMatch”：{“ key”：“ firebase_screen_class”}}}））