（06）mongodb 游标与分页

遍历1：

> var mycursor=db.person.find();
> while(mycursor.hasNext()){printjson(mycursor.next())}
{ "_id" : 1, "name" : "张三", "sex" : "男", "age" : 37.3 }
{ "_id" : 2, "name" : "张三", "sex" : "男", "age" : 27.3 }
{ "_id" : 3, "name" : "张三", "sex" : "男", "age" : 27.3 }
{ "_id" : 4, "name" : "李四", "class" : "三班", "score" : 90 }
{ "_id" : 5, "like" : "football", "name" : "王五" }
{
"_id" : ObjectId("5d4190e8c21b717496b2989b"),
"name" : "lisi",
"age" : 13,
"area" : "chaoyang",
"gender" : "male"
}
>

遍历2：

> var mycursor=db.person.find();
> mycursor.forEach(function(obj){printjson(obj)})
{ "_id" : 1, "name" : "张三", "sex" : "男", "age" : 37.3 }
{ "_id" : 2, "name" : "张三", "sex" : "男", "age" : 27.3 }
{ "_id" : 3, "name" : "张三", "sex" : "男", "age" : 27.3 }
{ "_id" : 4, "name" : "李四", "class" : "三班", "score" : 90 }
{ "_id" : 5, "like" : "football", "name" : "王五" }
{
"_id" : ObjectId("5d4190e8c21b717496b2989b"),
"name" : "lisi",
"age" : 13,
"area" : "chaoyang",
"gender" : "male"
}
>

分页：(skip、limit)；

db.person.find().skip((n-1)*m).limit(m); 查询第n页，每一页m条

> var mycursor=db.person.find().skip((1-1)*2).limit(2);　　共两页，第一页
> while(mycursor.hasNext()){printjson(mycursor.next())}
{ "_id" : 1, "name" : "张三", "sex" : "男", "age" : 37.3 }
{ "_id" : 2, "name" : "张三", "sex" : "男", "age" : 27.3 }
>
> var mycursor=db.person.find().skip((2-1)*2).limit(2);　　共两页，第二页
> while(mycursor.hasNext()){printjson(mycursor.next())}
{ "_id" : 3, "name" : "张三", "sex" : "男", "age" : 27.3 }
{ "_id" : 4, "name" : "李四", "class" : "三班", "score" : 90 }
>