MongoDB学习之旅八：MongoDB高级查询の游标使用

    游标使用

    象大多数数据库产品一样，MongoDB 也是用游标来循环处理每一条结果数据，具体语法如

下：

  > for( var c = db.t3.find(); c.hasNext(); ) {
     printjson( c.next());
    }
    { "_id" : ObjectId("4fb8e4838b2cb86417c9423a"), "age" : 1 }
    { "_id" : ObjectId("4fb8e4878b2cb86417c9423b"), "age" : 2 }
    { "_id" : ObjectId("4fb8e4898b2cb86417c9423c"), "age" : 3 }
    { "_id" : ObjectId("4fb8e48c8b2cb86417c9423d"), "age" : 4 }
    { "_id" : ObjectId("4fb8e48e8b2cb86417c9423e"), "age" : 5 }

     MongoDB 还有另一种方式来处理游标

    > db.t3.find().forEach( function(u) { printjson(u); } );
    { "_id" : ObjectId("4fb8e4838b2cb86417c9423a"), "age" : 1 }
    { "_id" : ObjectId("4fb8e4878b2cb86417c9423b"), "age" : 2 }
    { "_id" : ObjectId("4fb8e4898b2cb86417c9423c"), "age" : 3 }
    { "_id" : ObjectId("4fb8e48c8b2cb86417c9423d"), "age" : 4 }
    { "_id" : ObjectId("4fb8e48e8b2cb86417c9423e"), "age" : 5 }
    >