查找admin集合下前10条数据：
db.admin.find().limit(10);
---
插入数据
> post={table: "activityzones",
... fields: [
... {
... name: "_id",
... type: "ObjectId",
... hidden: true
... }]}
> db.admin.insert(post)
---
更新数据
post.comments=[]
db.admin.update({"table" : "appstore_accounts"},post)
---
删除数据
db.admin.remove("table" : "appstore_accounts")