MongoDB database query practical statement

Query the tuples that exist in the source_id attribute

db.getCollection('database name').find({source_id:{$exists:true}})

db.getCollection(‘mqtt_log’).find({source_id:{$exists:true}})

Query the tuple whose source_id attribute is a specific value

db.getCollection(‘api_log’).find({source_id:“777779014”})

Query tuples where the source_id attribute exists and create_time is in a certain period of time

db.getCollection('database name').find({source_id:, {$exists:true}create_time: {$gte: ISODate("2021-01-01T00:00:00Z"),$lte: ISODate("2021-01-28T00:00:00Z")}})

db.getCollection(‘api_log’).find({source_id:“777779014”, create_time:{$gte: ISODate("2021-01-01T00:00:00Z"),$lte: ISODate("2021-01-28T00:00:00Z")} })

db.getCollection(‘mqtt_log’).find({source_id:“1144606801”, create_time:{$gte: ISODate("2021-01-01T00:00:00Z"),$lte: ISODate("2021-01-28T00:00:00Z")} })