問(wèn)題

如果MongoDB 數(shù)據(jù)庫(kù)集合中僅存在一條記錄

{
“_id” : ObjectId(“5e6b4ef546b5f44e5c5b276d”),
“name” : “趙小明”,
“used_name” : [
“趙明”,
“趙小朋”
],
“age” : 16,
“gender” : 0,
“relatives” : [
{
“name” : “趙剛”,
“relationship” : 0
},
{
“name” : “秀英”,
“relationship” : 1
}
]
}