mongdb 如何操作子文檔數(shù)組 （查詢并返回子數(shù)組、增加或修改指定索引項）？

集合a中有以下文檔：

{
    "_id" : ObjectId("5acd77c763c9b117b48b2e92"),
    "Symbol" : "item01",
    "min5" : [ 
        {
            "Symbol" : "item01",
            "Date" : "2017-01-31",
            "price" : 5000
        }, 
        {
            "Symbol" : "item01",
            "Date" : "2017-01-30",
            "price" : 4999
        }, 
         {
            "Symbol" : "item01",
            "Date" : "2017-01-29",
            "price" : 4998
        }
        ...
    ],
    "min10" : [ 
        {
            "Symbol" : "item01",
            "Date" : "2017-01-31",
            "price" : 5010
        }, 
        {
            "Symbol" : "item01",
            "Date" : "2017-01-30",
            "price" : 5009
        }, 
         {
            "Symbol" : "item01",
            "Date" : "2017-01-29",
            "price" : 5008
        }
        ...
    ]
}
{
    "_id" : ObjectId("5acd77c763c9b117b48b2e91"),
    "Symbol" : "item02",
    "min5" : [ 
        {
            "Symbol" : "item02",
            "Date" : "2017-01-31",
            "price" : 2000
        }, 
        {
            "Symbol" : "item02",
            "Date" : "2017-01-30",
            "price" : 1999
        }, 
         {
            "Symbol" : "item02",
            "Date" : "2017-01-29",
            "price" : 1998
        }
        ...
    ],
    "min10" : [ 
        {
            "Symbol" : "item02",
            "Date" : "2017-01-31",
            "price" : 2010
        }, 
        {
            "Symbol" : "item02",
            "Date" : "2017-01-30",
            "price" : 2009
        }, 
         {
            "Symbol" : "item02",
            "Date" : "2017-01-29",
            "price" : 2008
        }
        ...
    ]
}
{
    "_id" : ObjectId("5acd77c763c9b117b48b2e90"),
    "Symbol" : "item03",
    "min5" : [ 
        {
            "Symbol" : "item03",
            "Date" : "2017-01-31",
            "price" : 3000
        }, 
        {
            "Symbol" : "item03",
            "Date" : "2017-01-30",
            "price" : 2999
        }, 
         {
            "Symbol" : "item03",
            "Date" : "2017-01-29",
            "price" : 2998
        }
        ...
    ],
    "min10" : [ 
        {
            "Symbol" : "item03",
            "Date" : "2017-01-31",
            "price" : 3010
        }, 
        {
            "Symbol" : "item03",
            "Date" : "2017-01-30",
            "price" : 3009
        }, 
         {
            "Symbol" : "item03",
            "Date" : "2017-01-29",
            "price" : 3008
        }
        ...
    ]
}

請問給定以下條件：
item02、 min5、 返回2條，如何查詢并返回以下格式的內(nèi)容：

[{"Symbol":"item02","Date":"2017-01-31","price":2000},{"Symbol":"item02","Date":"2017-01-30","price":1999}]

還有怎樣按數(shù)組的index操作子文檔數(shù)組里的item成員，增刪改查。

我使用的是Node.js中的mongodb包。

在網(wǎng)上和文檔里查了好久仍然不解，謝謝大神指點迷津，謝謝大家！