sqlserver使用clr调用ajax，在数据库内请求外部链接

sqlserver使用clr调用ajax，在数据库内请求外部链接

2019年09月11日 14:52:48 文盲老顾 阅读数 12 文章标签： clrajax外部链接sql函数 更多

分类专栏： .net clr sql

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本文链接：https://blog.csdn.net/superwfei/article/details/100735416

第一步：使用vs新建一个类库项目，编写clr程序集

1. using Microsoft.SqlServer.Server;

2. using System;

3. using System.Collections;

4. using System.Data.SqlTypes;

5. using System.Diagnostics.CodeAnalysis;

6. using System.IO;

7. using System.IO.Compression;

8. using System.Net;

9. using System.Text;

10. using System.Text.RegularExpressions;

11.  

12. internal class AjaxResult

13. {

14. private int _statusCode;

15. private string _url;

16. private string _html;

17. public string Url

18. {

19. get

20. {

21. return _url;

22. }

23. }

24. public string Html

25. {

26. get

27. {

28. return _html;

29. }

30. }

31. public int StatusCode

32. {

33. get

34. {

35. return _statusCode;

36. }

37. }

38. public AjaxResult(string url, string html, int statusCode)

39. {

40. _url = url;

41. _html = html;

42. _statusCode = statusCode;

43. }

44. }

45. internal class AjaxIterator : IEnumerable

46. {

47. private string _url;

48. private string _method;

49. private string _arguments;

50. public AjaxIterator(string url, string method, string arguments)

51. {

52. _url = url;

53. _method = method;

54. _arguments = arguments;

55. }

56. public IEnumerator GetEnumerator()

57. {

58. Ajax ajax = new Ajax();

59. ajax.Http(_url, _method.ToLower(), _arguments);

60. string url = ajax.CurrentUrl;

61. string html = ajax.Result;

62. int statusCode = (int)ajax.StatusCode;

63. yield return new AjaxResult(url, html, statusCode);

64. }

65. }

66. public static partial class ajax

67. {

68. [SqlFunction(FillRowMethodName = "FillAjaxRow", TableDefinition = "url nvarchar(500),html nvarchar(max),statusCode int")]

69. public static IEnumerable Http(SqlString url, SqlString method, SqlString arguments)

70. {

71. return new AjaxIterator(url.Value, method.Value, arguments.Value);

72. }

73. [SuppressMessage("Microsoft.Design", "CA1021:AvoidOutParameters")]

74. public static void FillAjaxRow(object data, out SqlString url, out SqlString html, out SqlInt32 statusCode)

75. {

76. AjaxResult node = (AjaxResult)data;

77. url = new SqlString(node.Url);

78. html = new SqlString(node.Html);

79. statusCode = new SqlInt32(node.StatusCode);

80. }

81. }

82. public class Ajax

83. {

84. private string _url = string.Empty;

85. private string _result = "";

86. private HttpStatusCode hsc = HttpStatusCode.OK;

87. public string CurrentUrl

88. {

89. get

90. {

91. return _url;

92. }

93. }

94. public string Result

95. {

96. get

97. {

98. return _result;

99. }

100. }

101. public HttpStatusCode StatusCode

102. {

103. get

104. {

105. return hsc;

106. }

107. }

108. private Encoding GetEncoding(string html)

109. {

110. if (Regex.IsMatch(html, @"(?<=<meta(?!\w)[^<>]*?)charset\s*=", RegexOptions.IgnoreCase))

111. {

112. string c = Regex.Match(html, @"(?<=<meta(?!\w)[^<>]*?charset\s*=\s*['""]?(?!['""]))\w[^\s'""/<>]*", RegexOptions.IgnoreCase).Value;

113. try

114. {

115. Encoding en = Encoding.GetEncoding(Regex.Match(html, @"(?<=<meta(?!\w)[^<>]*?charset\s*=\s*['""]?(?!['""]))\w[^\s'""/<>]*", RegexOptions.IgnoreCase).Value);

116. return en;

117. }

118. catch

119. {

120. return null;

121. }

122. }

123. else

124. {

125. return null;

126. }

127. }

128. public void Http(string url, string method, string QueryString)

129. {

130. string full_url = (("get" == method) ? ((QueryString.Length > 0) ? ((url.IndexOf("?") > 0) ? (url + "&" + QueryString) : (url + "?" + QueryString)) : url) : url);

131. ServicePointManager.Expect100Continue = false;

132. ServicePointManager.DefaultConnectionLimit = Int32.MaxValue;

133. string html = "";

134. HttpWebRequest http = (HttpWebRequest)WebRequest.Create(full_url);

135. http.AllowAutoRedirect = true;

136. http.UserAgent = "Mozilla/5.0 (Windows NT 5.1; rv:11.0) Gecko/20100101 Firefox/11.0";

137. http.Accept = "*/*";

138. http.KeepAlive = false;

139. http.Headers.Add("Accept-Encoding", "gzip, deflate");

140. _url = url;

141. if (method == "post")

142. {

143. http.Method = "POST";

144. http.Accept = "application/json, text/javascript, */*";

145. http.KeepAlive = true;

146. byte[] pd = null;

147. pd = new UTF8Encoding().GetBytes(QueryString);

148. try

149. {

150. http.ContentType = "application/x-www-form-urlencoded";

151. http.ContentLength = pd.Length;

152. Stream ps = http.GetRequestStream();

153. ps.Write(pd, 0, pd.Length);

154. ps.Close();

155. ps.Dispose();

156. }

157. catch (Exception ex)

158. {

159. _result = ex.Message;

160. hsc = HttpStatusCode.BadRequest;

161. return;

162. }

163. }

164. try

165. {

166. HttpWebResponse hwr = (HttpWebResponse)http.GetResponse();

167. hsc = hwr.StatusCode;

168. Stream s = hwr.GetResponseStream();

169. MemoryStream ms = new MemoryStream();

170. string contentType = "normal";

171. if (hwr.Headers.GetValues("Content-Encoding") != null)

172. {

173. string[] encd = hwr.Headers.GetValues("Content-Encoding");

174. for (int i = 0; i < encd.Length; i++)

175. {

176. if (encd[i] == "gzip")

177. {

178. contentType = "gzip";

179. break;

180. }

181. if (encd[i] == "deflate")

182. {

183. contentType = "deflate";

184. break;

185. }

186. }

187. }

188. switch (contentType)

189. {

190. case "deflate":

191. DeflateStream ds = new DeflateStream(s, CompressionMode.Decompress);

192. ds.CopyTo(ms);

193. ds.Close();

194. ds.Dispose();

195. break;

196. case "gzip":

197. GZipStream g = new GZipStream(s, CompressionMode.Decompress);

198. g.CopyTo(ms);

199. g.Close();

200. g.Dispose();

201. break;

202. default:

203. s.CopyTo(ms);

204. break;

205. }

206. s.Close();

207. s.Dispose();

208. byte[] bt = ms.ToArray();

209. ms.Close();

210. ms.Dispose();

211. html = Encoding.UTF8.GetString(bt);

212. Encoding en_test = GetEncoding(html);

213. if (en_test != null && en_test != Encoding.UTF8)

214. {

215. html = en_test.GetString(bt);

216. }

217. _result = html;

218. hwr.Close();

219. }

220. catch (WebException ex)

221. {

222. if (ex.Response == null)

223. {

224. hsc = HttpStatusCode.BadRequest;

225. _result = ex.Message;

226. return;

227. }

228. hsc = ((HttpWebResponse)ex.Response).StatusCode;

229. _result = ex.Message;

230. }

231. }

232. }

在这个类库随便命名了，编写好之后生成或发布

第二步：导入程序集

在sql server management studio里，找到你要操作的数据库 -> 可编程性 -> 程序集 -> 鼠标右键 -> 新建程序集

弹出上图所示的对话框，点浏览选择之前生成的dll文件

第三步：创建一个自定义函数，调用clr程序集

1. CREATE FUNCTION [dbo].[Ajax](@url [nvarchar](max), @method [nvarchar](max), @arguments [nvarchar](max))

2. RETURNS TABLE (

3. [url] [nvarchar](500) NULL,

4. [html] [nvarchar](max) NULL,

5. [statusCode] [int] NULL

6. ) WITH EXECUTE AS CALLER

7. AS

8. EXTERNAL NAME [clr.ajax].[ajax].[Http]

这里，external name 之后的三个数据分别是[clr类库项目名].[clr类名].[方法名]

如图所示，我创建的clr项目名是clr.ajax，所以生成的dll是clr.ajax.dll，引用的方法就是[clr.ajax].[ajax].[Http]

第四步：设置数据库权限，允许进行外部访问

1. -- 设置clr enabled允许调用clr程序

2. sp_configure 'clr enabled',1

3. go

4. reconfigure

5. go

6. -- 设置数据库允许方位外部

7. alter database [dbname] set trustworthy on

8. go

9. -- 修改程序集的设置，将权限集设置为外部访问

10. -- 通过sqlserver management studio的界面修改

这里的dbname就是你之前导入程序集的数据库了

第五步：使用自定义函数访问外部链接

自定义函数有三个参数，第一个参数是url，第二个是method，也就是谓词，比如get、post，第三个是参数集，上图已有示例了

如果使用过程中报错，请参考SQL Server 2005 CLR 调用Web Service需要注意的几个问题

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Hmm.....写这么个clr，可不是为了让数据库去玩采集，是为了偷懒！

什么时候用数据库去ajax呢？举几个例子：

静态页网站，当数据库更新后，用触发器或队列调用更新静态页的程序

第三方设置，当本地数据库修改设置后，同步到第三方时

token更新等

注意，可千万别再数据库里玩批量采集哦