我创建了一个 CLR 用户定义函数来使用 Google 地理编码查找某个位置的纬度和经度信息。功能如下:
using System;
using System.Net;
using System.Xml.XPath;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading;
using System.Data.SqlClient;
using System.Data.SqlTypes;
using Microsoft.SqlServer.Server;
public partial class latlong
{
[Microsoft.SqlServer.Server.SqlFunction]
public static SqlString GetLatLong(string address, string city, string state, string zip)
{
string latitude = "#NA", longitude = "#NA";
string url = "http://maps.googleapis.com/maps/api/geocode/xml?address=";
string[] addresssplit = Regex.Split(address, @"\W+");
if (address != "NULL")
for (int i = 0; i < addresssplit.Length; i++)
url = url + addresssplit[i] + "+";
if (city != "NULL")
{
if (state != "NULL")
{
if (zip != "NULL") url = url + city + "+" + state + "+" + zip;
else url = url + city + "+" + state;
}
else
{
if (zip!= "NULL") url = url + city + "+" + zip;
else url = url + city;
}
}
else
{
if (state != "NULL")
{
if (zip != "NULL") url = url + state + "+" + zip;
else url = url + state;
}
else
{
if (zip != "NULL") url = url + zip;
}
}
url = url + "&sensor=false";
WebResponse response = null;
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
request.Method = "GET";
response = request.GetResponse();
if (response != null)
{
XPathDocument document = new XPathDocument(response.GetResponseStream());
XPathNavigator navigator = document.CreateNavigator();
XPathNodeIterator statusIterator = navigator.Select("/GeocodeResponse/status");
while (statusIterator.MoveNext())
if (statusIterator.Current.Value != "OK")
{
Thread.Sleep(1000);
return new SqlString("OQL, OQL");
}
XPathNodeIterator resultIterator = navigator.Select("/GeocodeResponse/result");
while (resultIterator.MoveNext())
{
XPathNodeIterator geometryIterator = resultIterator.Current.Select("geometry");
while (geometryIterator.MoveNext())
{
XPathNodeIterator locationIterator = geometryIterator.Current.Select("location");
while (locationIterator.MoveNext())
{
XPathNodeIterator latIterator = locationIterator.Current.Select("lat");
while (latIterator.MoveNext())
latitude = latIterator.Current.Value;
XPathNodeIterator longIterator = locationIterator.Current.Select("long");
while (longIterator.MoveNext())
longitude = longIterator.Current.Value;
}
}
}
}
Thread.Sleep(1000);
return new SqlString(latitude + ", " + longitude);
}
}
我已经成功构建并部署了该功能。所以我尝试在 SQL 服务器中执行该函数,如下所示:
SELECT dba.dbo.GetLatLong('3366 Cherry Avenue','Zion','WI','54963')
当我这样做时,会引发以下安全表达式
A .NET Framework error occurred during execution of user-defined routine or aggregate "GetLatLong":
System.Security.SecurityException: Request for the permission of type 'System.Net.WebPermission, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' failed.
System.Security.SecurityException:
at System.Security.CodeAccessSecurityEngine.Check(Object demand, StackCrawlMark& stackMark, Boolean isPermSet)
at System.Security.CodeAccessPermission.Demand()
at System.Net.HttpWebRequest..ctor(Uri uri, ServicePoint servicePoint)
at System.Net.HttpRequestCreator.Create(Uri Uri)
at System.Net.WebRequest.Create(Uri requestUri, Boolean useUriBase)
at latlong.GetLatLong(String address, String city, String state, String zip).
我可以看到安全权限有问题。但除此之外,我看不到修复异常的方法。
任何帮助表示赞赏。