切换库>use库名switchedtodbcompany创建：1.post={"title":"lzgtitle","context":"wodewenbenxinxi","date":newDate()};2.db.blog.insert(post);读取db.blog.find();db.blog.findOne();更新1.post.cruser="lzgadmin";2.db.blog.update({"title":"lzgtitle"},po