show dbs # 从结果中发现有cmb_demo_23_hackeruse cmb_demo_23_hacker db.all_in_one.find({"_id":15480},{"raw_doc.text_html":1})
然后我想看看cmb_demo_23_hacker里面有多少篇文章> show collections #相当于查看表名all_in_onees
> db.all_in_one.find({}).count()575324