{"id":60247,"date":"2024-10-13T01:16:17","date_gmt":"2024-10-12T17:16:17","guid":{"rendered":"https:\/\/server.hk\/cnblog\/60247\/"},"modified":"2024-10-13T01:16:17","modified_gmt":"2024-10-12T17:16:17","slug":"datareader%e7%9a%84%e9%97%9c%e9%96%89%e5%95%8f%e9%a1%8c%e7%96%91%e6%83%91%e7%af%87","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/60247\/","title":{"rendered":"DataReader\u7684\u95dc\u9589\u554f\u984c\u7591\u60d1\u7bc7"},"content":{"rendered":"<h1 id=\"datareader%e7%9a%84%e9%97%9c%e9%96%89%e5%95%8f%e9%a1%8c%e7%96%91%e6%83%91%e7%af%87-wgmdlEInSh\">DataReader\u7684\u95dc\u9589\u554f\u984c\u7591\u60d1\u7bc7<\/h1>\n<p>\u5728\u4f7f\u7528ADO.NET\u9032\u884c\u6578\u64da\u5eab\u64cd\u4f5c\u6642\uff0c<code>DataReader<\/code>\u662f\u4e00\u500b\u975e\u5e38\u91cd\u8981\u7684\u7d44\u4ef6\u3002\u5b83\u63d0\u4f9b\u4e86\u4e00\u7a2e\u9ad8\u6548\u7684\u65b9\u5f0f\u4f86\u8b80\u53d6\u6578\u64da\uff0c\u4f46\u5728\u4f7f\u7528\u904e\u7a0b\u4e2d\uff0c\u8a31\u591a\u958b\u767c\u8005\u5c0d\u65bc<code>DataReader<\/code>\u7684\u95dc\u9589\u554f\u984c\u5b58\u5728\u7591\u60d1\u3002\u672c\u6587\u5c07\u6df1\u5165\u63a2\u8a0e<code>DataReader<\/code>\u7684\u95dc\u9589\u554f\u984c\uff0c\u4e26\u63d0\u4f9b\u4e00\u4e9b\u6700\u4f73\u5be6\u8e10\u548c\u793a\u4f8b\u4ee3\u78bc\u3002<\/p>\n<h2 id=\"%e4%bb%80%e9%ba%bc%e6%98%afdatareader%ef%bc%9f-wgmdlEInSh\">\u4ec0\u9ebc\u662fDataReader\uff1f<\/h2>\n<p><code>DataReader<\/code>\u662fADO.NET\u4e2d\u7684\u4e00\u500b\u985e\uff0c\u7528\u65bc\u4ee5\u53ea\u9032\u884c\u7684\u65b9\u5f0f\u5f9e\u6578\u64da\u5eab\u4e2d\u8b80\u53d6\u6578\u64da\u3002\u5b83\u7684\u4e3b\u8981\u7279\u9ede\u662f\u9ad8\u6548\u548c\u8f15\u91cf\uff0c\u9069\u5408\u7528\u65bc\u9700\u8981\u5feb\u901f\u8b80\u53d6\u5927\u91cf\u6578\u64da\u7684\u5834\u666f\u3002<code>DataReader<\/code>\u7684\u4f7f\u7528\u901a\u5e38\u8207<code>SqlCommand<\/code>\u548c<code>SqlConnection<\/code>\u4e00\u8d77\u9032\u884c\u3002<\/p>\n<h2 id=\"datareader%e7%9a%84%e4%bd%bf%e7%94%a8%e6%b5%81%e7%a8%8b-wgmdlEInSh\">DataReader\u7684\u4f7f\u7528\u6d41\u7a0b<\/h2>\n<p>\u4f7f\u7528<code>DataReader<\/code>\u7684\u57fa\u672c\u6d41\u7a0b\u5982\u4e0b\uff1a<\/p>\n<ol>\n<li>\u5efa\u7acb\u6578\u64da\u5eab\u9023\u63a5\u3002<\/li>\n<li>\u5275\u5efa<code>SqlCommand<\/code>\u5c0d\u8c61\u3002<\/li>\n<li>\u57f7\u884c\u547d\u4ee4\u4e26\u7372\u53d6<code>DataReader<\/code>\u3002<\/li>\n<li>\u8b80\u53d6\u6578\u64da\u3002<\/li>\n<li>\u95dc\u9589<code>DataReader<\/code>\u548c\u6578\u64da\u5eab\u9023\u63a5\u3002<\/li>\n<\/ol>\n<h3 id=\"%e7%a4%ba%e4%be%8b%e4%bb%a3%e7%a2%bc-wgmdlEInSh\">\u793a\u4f8b\u4ee3\u78bc<\/h3>\n<pre><code>\nusing (SqlConnection connection = new SqlConnection(connectionString))\n{\n    connection.Open();\n    SqlCommand command = new SqlCommand(\"SELECT * FROM Users\", connection);\n    \n    using (SqlDataReader reader = command.ExecuteReader())\n    {\n        while (reader.Read())\n        {\n            Console.WriteLine(reader[\"Username\"]);\n        }\n    } \/\/ \u9019\u88e1\u6703\u81ea\u52d5\u95dc\u9589DataReader\n} \/\/ \u9019\u88e1\u6703\u81ea\u52d5\u95dc\u9589Connection\n<\/code><\/pre>\n<h2 id=\"datareader%e7%9a%84%e9%97%9c%e9%96%89%e5%95%8f%e9%a1%8c-wgmdlEInSh\">DataReader\u7684\u95dc\u9589\u554f\u984c<\/h2>\n<p>\u5728\u4f7f\u7528<code>DataReader<\/code>\u6642\uff0c\u958b\u767c\u8005\u5e38\u5e38\u6703\u554f\uff1a<code>DataReader<\/code>\u662f\u5426\u9700\u8981\u624b\u52d5\u95dc\u9589\uff1f\u7b54\u6848\u662f\uff1a\u4e0d\u9700\u8981\u3002\u7576<code>DataReader<\/code>\u7684\u7bc4\u570d\u7d50\u675f\u6642\uff0c\u6703\u81ea\u52d5\u95dc\u9589\u3002\u9019\u662f\u56e0\u70ba\u5728\u4f7f\u7528<code>using<\/code>\u8a9e\u53e5\u6642\uff0c<code>DataReader<\/code>\u6703\u5be6\u73fe<code>IDisposable<\/code>\u63a5\u53e3\uff0c\u4e26\u5728\u7bc4\u570d\u7d50\u675f\u6642\u81ea\u52d5\u91cb\u653e\u8cc7\u6e90\u3002<\/p>\n<h3 id=\"%e7%82%ba%e4%bb%80%e9%ba%bc%e8%a6%81%e9%97%9c%e9%96%89datareader%ef%bc%9f-wgmdlEInSh\">\u70ba\u4ec0\u9ebc\u8981\u95dc\u9589DataReader\uff1f<\/h3>\n<p>\u96d6\u7136<code>DataReader<\/code>\u6703\u81ea\u52d5\u95dc\u9589\uff0c\u4f46\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\uff0c\u958b\u767c\u8005\u53ef\u80fd\u6703\u9078\u64c7\u624b\u52d5\u95dc\u9589\u3002\u9019\u901a\u5e38\u767c\u751f\u5728\u9700\u8981\u63d0\u524d\u7d42\u6b62\u6578\u64da\u8b80\u53d6\u7684\u60c5\u6cc1\u4e0b\u3002\u4f8b\u5982\uff0c\u5982\u679c\u5728\u8b80\u53d6\u904e\u7a0b\u4e2d\u767c\u751f\u4e86\u932f\u8aa4\uff0c\u958b\u767c\u8005\u53ef\u80fd\u5e0c\u671b\u7acb\u5373\u91cb\u653e\u8cc7\u6e90\u3002<\/p>\n<h3 id=\"%e6%89%8b%e5%8b%95%e9%97%9c%e9%96%89%e7%9a%84%e7%a4%ba%e4%be%8b-wgmdlEInSh\">\u624b\u52d5\u95dc\u9589\u7684\u793a\u4f8b<\/h3>\n<pre><code>\nSqlDataReader reader = null;\ntry\n{\n    reader = command.ExecuteReader();\n    while (reader.Read())\n    {\n        \/\/ \u8b80\u53d6\u6578\u64da\n    }\n}\ncatch (Exception ex)\n{\n    \/\/ \u8655\u7406\u7570\u5e38\n}\nfinally\n{\n    if (reader != null)\n    {\n        reader.Close(); \/\/ \u624b\u52d5\u95dc\u9589\n    }\n}\n<\/code><\/pre>\n<h2 id=\"%e6%9c%80%e4%bd%b3%e5%af%a6%e8%b8%90-wgmdlEInSh\">\u6700\u4f73\u5be6\u8e10<\/h2>\n<ul>\n<li>\u59cb\u7d42\u4f7f\u7528<code>using<\/code>\u8a9e\u53e5\u4f86\u7ba1\u7406<code>DataReader<\/code>\u548c<code>SqlConnection<\/code>\u7684\u751f\u547d\u9031\u671f\u3002<\/li>\n<li>\u5728\u8b80\u53d6\u6578\u64da\u6642\uff0c\u76e1\u91cf\u907f\u514d\u9577\u6642\u9593\u6301\u6709<code>DataReader<\/code>\uff0c\u4ee5\u514d\u5f71\u97ff\u6578\u64da\u5eab\u7684\u6027\u80fd\u3002<\/li>\n<li>\u5728\u7570\u5e38\u8655\u7406\u4e2d\uff0c\u78ba\u4fdd<code>DataReader<\/code>\u80fd\u5920\u88ab\u6b63\u78ba\u95dc\u9589\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b8%bd%e7%b5%90-wgmdlEInSh\">\u7e3d\u7d50<\/h2>\n<p>\u5728\u4f7f\u7528<code>DataReader<\/code>\u6642\uff0c\u7406\u89e3\u5176\u95dc\u9589\u554f\u984c\u662f\u975e\u5e38\u91cd\u8981\u7684\u3002\u901a\u904e\u6b63\u78ba\u7684\u4f7f\u7528\u65b9\u5f0f\u548c\u6700\u4f73\u5be6\u8e10\uff0c\u53ef\u4ee5\u6709\u6548\u5730\u7ba1\u7406\u8cc7\u6e90\uff0c\u63d0\u5347\u61c9\u7528\u7a0b\u5e8f\u7684\u6027\u80fd\u3002\u5982\u679c\u60a8\u5c0d\u65bc<code>DataReader<\/code>\u6216\u5176\u4ed6\u6578\u64da\u5eab\u64cd\u4f5c\u6709\u9032\u4e00\u6b65\u7684\u9700\u6c42\uff0c\u6b61\u8fce\u8a2a\u554f\u6211\u5011\u7684\u7db2\u7ad9\u4e86\u89e3\u66f4\u591a\u8cc7\u8a0a\uff0c\u7279\u5225\u662f\u6211\u5011\u7684<a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a>\u89e3\u6c7a\u65b9\u6848\uff0c\u80fd\u5920\u70ba\u60a8\u7684\u61c9\u7528\u63d0\u4f9b\u7a69\u5b9a\u7684\u652f\u6301\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u63a2\u8a0eDataReader\u95dc\u9589\u554f\u984c\u7684\u5e38\u898b\u7591\u60d1\uff0c\u63d0\u4f9b\u89e3\u7b54\u8207\u6700\u4f73\u5be6\u8e10\uff0c\u5e6b\u52a9\u958b\u767c\u8005\u6709\u6548\u7ba1\u7406\u8cc7\u6599\u9023\u63a5\u3002<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-60247","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/60247","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=60247"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/60247\/revisions"}],"predecessor-version":[{"id":60248,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/60247\/revisions\/60248"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=60247"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=60247"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=60247"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}