下面哪一个是正确的 MongoDB JSON document 格式__?

选择了： {}

选择了： { "user_id":1, "user_name":"Joe Sanders", "occupation": [ "occupation1":"engineer", "occupation2":"writer" ] }

选择了： { "user_id":1, "user_name":"Joe Sanders", "occupation": [ "occupation1":"engineer", "occupation2":"writer" ] }

选择了： {}

选择了： {}

选择了： { "user_id"=1, "user_name"="Joe Sanders", "occupation"=["engineer","writer"] }

选择了： { "user_id":1; "user_name":"Joe Sanders"; "occupation":["engineer","writer"] }

选择了： { "user_id":1, "user_name":"Joe Sanders", "occupation": [ "occupation1":"engineer", "occupation2":"writer" ] }

选择了： {}

选择了： { "user_id":1, "user_name":"Joe Sanders", "occupation": [ "occupation1":"engineer", "occupation2":"writer" ] }