插入文档

向集合中插入一个文档（类比向表中插入一条数据）：

 `db.getCollection("b2b_theme_activity").insert( { 

  "merchant_code": "1ed0528595197975fa72f5ec8f9e0c62",

  "dfx_type": NumberInt("1"),

  "create_time": ISODate("2020-03-16T22:36:01.964Z"),

  "member_code": "e69e61a77b1ccc7b90be7995c6a6021f",

  "user_name": "李郃",

  "merchant_name": "南京好享家智能家居有限公司",

  source: NumberInt("10"),

  "visit_duration": "",

  type: NumberInt("11"),

  "member_name": "测试企业开户01",

  "theme_activity_page_title": "测试test01",

  "login_name": "17366180925",

  "user_id": "1161150535707852801",

  event: NumberInt("20"),

  "theme_activity_id": "1238383672212533250"

} );