用Facebook Query Language查出讚的點擊率

2011-10-23

越來越多網站會使用Facebook的讚當作人氣指標

而Facebook也提供了許多種API讓使用者可以得到這些統計的資訊

今天來介紹用FQL(Facebook Query Language)來取得某一網址讚的點擊數

FQL的格式跟SQL很像，是以SELECT [fields] FROM [table] WHERE [conditions]這樣

的格式運作。例如以今天的範例來說，要下的語法就是：


SELECT like_count, share_count, click_count, total_count 
from link_stat where url="目標的URL"

官網的API還有提供許多用法，請參考Facebook Query Language (FQL)

將組合的FQL配上


https://api.facebook.com/method/fql.query?query=[FQL]

而返回的XML就會將所查詢的資訊帶回。

下面的範例我用黃偉榮的學習筆記的[C#]列舉切割器(IEnumerable Split)這篇文章來作範例

查詢這篇文章的讚及分享等統計


string api="https://api.facebook.com/method/fql.query?query=";

//FQL，where url為目標網址
string url ="SELECT like_count, share_count, click_count, total_count from link_stat  where  url=\"{0}\"";

//要統計的網址
string targetUrl="http://www.dotblogs.com.tw/wadehuang36/archive/2011/08/02/ienumerablesplit.aspx";

//做UrlPathEncode
string fql = HttpUtility.UrlPathEncode(String.Format(url,targetUrl));

組合出來的連結會是下面這樣

https://api.facebook.com/method/fql.query?query=SELECT%20like_count,%20share_count,%20click_count,%20total_count%20
from%20link_stat%20%20where%20%20url="http://www.dotblogs.com.tw/wadehuang36/archive/2011/08/02/ienumerablesplit.aspx"

接著建立一個WebRequest，將Url送出，然後接收WebResponse


WebRequest request= WebRequest.Create(String.Concat(api,fql));

using(WebResponse response = request.GetResponse())
using(Stream stream=response.GetResponseStream())
{
    //...處理返回的Stream
}

如果將返回的Stream讀出來的話，可看到是一個XML的格式


<?xml version="1.0" encoding="UTF-8"?>
<fql_query_response xmlns="http://api.facebook.com/1.0/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" list="true">
  <link_stat>
    <like_count>5</like_count>
    <share_count>1</share_count>
    <click_count>0</click_count>
    <total_count>6</total_count>
  </link_stat>
</fql_query_response>

從XML看到這邊文章被點了5次讚，然後1人分享連結。

返回來的Stream可以用Linq to Xml來處理，也可以將Class訂好，用反序列化的方式轉為Class


[XmlRootAttribute("fql_query_response", Namespace="http://api.facebook.com/1.0/")]
public class FBQuery
{
	[XmlElementAttribute("link_stat")]
	public LinkState State { get; set; }
}

public class LinkState
{
	[XmlElementAttribute("like_count")]
	public int LikeCount { get; set; }
	[XmlElementAttribute("share_count")]
	public int ShareCount { get; set; }
	[XmlElementAttribute("click_count")]
	public int ClickCount { get; set; }
	[XmlElementAttribute("total_count")]
	public int TotalCcount { get; set; }
}

處理Stream


XmlSerializer xml = new XmlSerializer(typeof(FBQuery));

var result = xml.Deserialize(stream) as FBQuery;

結果

完整的Code


void Main()
{

	string api="https://api.facebook.com/method/fql.query?query=";

	//FQL，where url為目標網址
	string url ="SELECT like_count, share_count, click_count, total_count from link_stat  where  url=\"{0}\"";
	
	//要統計的網址
	string targetUrl="http://www.dotblogs.com.tw/wadehuang36/archive/2011/08/02/ienumerablesplit.aspx";
	
	//做UrlPathEncode
	string fql = HttpUtility.UrlPathEncode(String.Format(url,targetUrl));
	
	//建立WebRequest
	WebRequest request= WebRequest.Create(String.Concat(api,fql));

	using(WebResponse response = request.GetResponse())
	using(Stream stream=response.GetResponseStream())
	{
		XmlSerializer xml = new XmlSerializer(typeof(FBQuery));
		
		var result = xml.Deserialize(stream) as FBQuery;
	}
}

[XmlRootAttribute("fql_query_response", Namespace="http://api.facebook.com/1.0/")]
public class FBQuery
{
	[XmlElementAttribute("link_stat")]
	public LinkState State { get; set; }
}

public class LinkState
{
	[XmlElementAttribute("like_count")]
	public int LikeCount { get; set; }
	[XmlElementAttribute("share_count")]
	public int ShareCount { get; set; }
	[XmlElementAttribute("click_count")]
	public int ClickCount { get; set; }
	[XmlElementAttribute("total_count")]
	public int TotalCcount { get; set; }
}

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