知识大全 SQL2005CLR函数扩展-解析天气服务的实现

Posted 2022-07-15 函数

篇首语：锲而舍之，朽木不折；锲而不舍，金石可镂。本文由小常识网(cha138.com)小编为大家整理，主要介绍了知识大全 SQL2005CLR函数扩展-解析天气服务的实现相关的知识，希望对你有一定的参考价值。

SQL2005CLR函数扩展-解析天气服务的实现 以下文字资料是由(全榜网网www.cha138.com)小编为大家搜集整理后发布的内容，让我们赶快一起来看一下吧！

　　我们可以用CLR获取网络服务来显示到数据库自定函数的结果集中比如的天气预报他的这个xml结果的日期是不正确的但这个我们暂不讨论从这个xml获取天气的CLR代码如下用WebClient访问一下就可以了然后通过Dom对象遍历节点属性返回给结果集

复制代码代码如下: using System; using System Data; using System Data SqlClient; using System Data SqlTypes; using System Collections; using System Collections Generic; using Microsoft SqlServer Server; public partial class UserDefinedFunctions [SqlFunction (TableDefinition = "city nvarchar( ) date nvarchar( ) general nvarchar( ) temperature nvarchar( ) wind nvarchar( )" Name = "GetWeather" FillRowMethodName = "FillRow" )] public static IEnumerable GetWeather() System Collections Generic List <Item > list = GetData(); return list; public static void FillRow(Object obj out SqlString city out SqlString date out SqlString general out SqlString temperature out SqlString wind) Item data = (Item )obj; city = data city; date = data date; general = data general; temperature = data temperature; wind = data wind; class Item public string city; public string date; public string general; public string temperature; public string wind; static System Collections Generic List <Item > GetData() System Collections Generic List <Item > ret = new List <Item >(); //try // string url = " System Net WebClient wb = new System Net WebClient (); byte [] b = wb DownloadData(url); string data = System Text Encoding Default GetString(b); System Xml XmlDocument doc = new System Xml XmlDocument (); doc LoadXml(data); foreach (System Xml XmlNode node in doc ChildNodes[ ]) string city = GetXMLAttrib(node "name" ); foreach (System Xml XmlNode subnode in node ChildNodes) Item item = new Item (); item city = city; item date = GetXMLAttrib(subnode "date" ); item general = GetXMLAttrib(subnode "general" ); item temperature = GetXMLAttrib(subnode "temperature" ); item wind = GetXMLAttrib(subnode "wind" ); ret Add(item); // //catch(Exception ex) // // SqlContext Pipe Send(ex Message); // return ret; static string GetXMLAttrib(System Xml XmlNode node string attrib) try return node Attributes[attrib] Value; catch return string Empty; ;

　　部署这个clr函数的脚本如下

复制代码代码如下: drop function dbo xfn_GetWeather drop ASSEMBLY TestWeather go CREATE ASSEMBLY TestWeather FROM d:/sqlclr/TestWeather dll WITH PERMISSION_SET = UnSAFE; go CREATE FUNCTION dbo xfn_GetWeather () RETURNS table ( city nvarchar ( ) date nvarchar ( ) general nvarchar ( ) temperature nvarchar ( ) wind nvarchar ( )) AS EXTERNAL NAME TestWeather UserDefinedFunctions GetWeather cha138/Article/program/MySQL/201311/29543