{"id":200702,"date":"2025-05-06T08:10:23","date_gmt":"2025-05-06T00:10:23","guid":{"rendered":"https:\/\/server.hk\/cnblog\/200702\/"},"modified":"2025-05-06T08:10:23","modified_gmt":"2025-05-06T00:10:23","slug":"%e4%bd%bf%e7%94%a8%e7%ad%96%e7%95%a5%e8%ae%be%e8%ae%a1%e6%a8%a1%e5%bc%8f%e5%88%86%e6%ad%a5%e6%8c%87%e5%8d%97%e5%9c%a8-c-%e4%b8%ad%e5%ae%9e%e7%8e%b0%e6%95%b0%e6%8d%ae%e5%ba%93%e5%8a%a9%e6%89%8b","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/200702\/","title":{"rendered":"\u4f7f\u7528\u7b56\u7565\u8bbe\u8ba1\u6a21\u5f0f\u5206\u6b65\u6307\u5357\u5728 C# \u4e2d\u5b9e\u73b0\u6570\u636e\u5e93\u52a9\u624b"},"content":{"rendered":"<p><b><\/b> <\/p>\n<h1>\u4f7f\u7528\u7b56\u7565\u8bbe\u8ba1\u6a21\u5f0f\u5206\u6b65\u6307\u5357\u5728 C# \u4e2d\u5b9e\u73b0\u6570\u636e\u5e93\u52a9\u624b<\/h1>\n<p>\u672c\u7bc7\u6587\u7ae0\u5411\u5927\u5bb6\u4ecb\u7ecd\u300a\u4f7f\u7528\u7b56\u7565\u8bbe\u8ba1\u6a21\u5f0f\u5206\u6b65\u6307\u5357\u5728 C# \u4e2d\u5b9e\u73b0\u6570\u636e\u5e93\u52a9\u624b\u300b\uff0c\u4e3b\u8981\u5305\u62ec\uff0c\u5177\u6709\u4e00\u5b9a\u7684\u53c2\u8003\u4ef7\u503c\uff0c\u9700\u8981\u7684\u670b\u53cb\u53ef\u4ee5\u53c2\u8003\u4e00\u4e0b\u3002<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.17golang.com\/uploads\/20241112\/17313827946732ce0a42028.jpg\" class=\"aligncenter\"><\/p>\n<p><strong>\u7b2c 1 \u6b65\uff1a\u5b9a\u4e49\u7b56\u7565\u63a5\u53e3<\/strong><\/p>\n<p>\u9996\u5148\u521b\u5efa\u4e00\u4e2a\u63a5\u53e3isqlstrategy\uff0c\u58f0\u660egetdatatable\u65b9\u6cd5\uff0c\u8be5\u65b9\u6cd5\u5c06\u7531\u4e0d\u540c\u7684\u6570\u636e\u5e93\u7b56\u7565\u5b9e\u73b0\u3002<\/p>\n<pre>using system.data;\n\nnamespace myproject.util\n{\n    public interface isqlstrategy\n    {\n        datatable getdatatable(string sql);\n    }\n}\n<\/pre>\n<p><strong>\u7b2c 2 \u6b65\uff1a\u5b9e\u65bd\u5177\u4f53\u7b56\u7565<\/strong><\/p>\n<p>\u63a5\u4e0b\u6765\uff0c\u4e3a\u6bcf\u79cd\u6570\u636e\u5e93\u7c7b\u578b\uff08mysql\u3001postgresql \u548c sql server\uff09\u5b9e\u73b0 isqlstrategy \u63a5\u53e3\u3002<\/p>\n<p>mysql \u7b56\u7565\uff1a<\/p>\n<pre>using mysql.data.mysqlclient;\nusing system;\nusing system.configuration;\nusing system.data;\n\nnamespace myproject.util\n{\n    public class mysqlquery : isqlstrategy\n    {\n        public datatable getdatatable(string sql)\n        {\n            try\n            {\n                using (mysqlconnection conn = new mysqlconnection(configurationmanager.appsettings[\"mysqlconnectionstring\"]))\n                {\n                    datatable dt = new datatable();\n                    conn.open();\n                    mysqlcommand command = new mysqlcommand(sql, conn);\n                    dt.load(command.executereader());\n                    conn.close();\n                    return dt;\n                }\n            }\n            catch (exception e)\n            {\n                console.writeline(e.tostring());\n                return null;\n            }\n        }\n    }\n}\n<\/pre>\n<p>postgresql \u7b56\u7565\uff1a<\/p>\n<pre>using npgsql;\nusing system;\nusing system.configuration;\nusing system.data;\n\nnamespace myproject.util\n{\n    public class npgsqlquery : isqlstrategy\n    {\n        public datatable getdatatable(string sql)\n        {\n            try\n            {\n                using (npgsqlconnection conn = new npgsqlconnection(configurationmanager.appsettings[\"npgsqlconnectionstring\"]))\n                {\n                    datatable dt = new datatable();\n                    conn.open();\n                    npgsqlcommand command = new npgsqlcommand(sql, conn);\n                    npgsqldataadapter _dap = new npgsqldataadapter(command);\n                    _dap.fill(dt);\n                    conn.close();\n                    return dt;\n                }\n            }\n            catch (exception e)\n            {\n                console.writeline(e.tostring());\n                return null;\n            }\n        }\n    }\n}\n<\/pre>\n<p>sql server \u7b56\u7565\uff1a<\/p>\n<pre>using system;\nusing system.configuration;\nusing system.data;\nusing system.data.sqlclient;\n\nnamespace myproject.util\n{\n    public class tsqlquery : isqlstrategy\n    {\n        public datatable getdatatable(string sql)\n        {\n            try\n            {\n                using (sqlconnection conn = new sqlconnection(configurationmanager.appsettings[\"tsqlconnectionstring\"]))\n                {\n                    datatable dt = new datatable();\n                    conn.open();\n                    sqlcommand command = new sqlcommand(sql, conn);\n                    sqldataadapter da = new sqldataadapter(command);\n                    da.fill(dt);\n                    conn.close();\n                    return dt;\n                }\n            }\n            catch (exception e)\n            {\n                console.writeline(e.tostring());\n                return null;\n            }\n        }\n    }\n}\n<\/pre>\n<p><strong>\u7b2c 3 \u6b65\uff1a\u521b\u5efa\u4e0a\u4e0b\u6587\u7c7b<\/strong><\/p>\n<p>sqlstrategy \u7c7b\u5c06\u4f7f\u7528 isqlstrategy \u7684\u5b9e\u4f8b\u6765\u6267\u884c\u6570\u636e\u5e93\u64cd\u4f5c\u3002<\/p>\n<pre>using system.data;\n\nnamespace myproject.util\n{\n    public class sqlstrategy\n    {\n        private readonly isqlstrategy _sqlstrategy;\n\n        public sqlstrategy(isqlstrategy sqlstrategy)\n        {\n            _sqlstrategy = sqlstrategy;\n        }\n\n        public datatable getdatatable(string sql)\n        {\n            return _sqlstrategy.getdatatable(sql);\n        }\n    }\n}\n<\/pre>\n<p><strong>\u7b2c 4 \u6b65\uff1a\u5b9e\u65bd\u5ba2\u6237\u7aef\u4ee3\u7801<\/strong><\/p>\n<p>\u6700\u540e\uff0c\u7f16\u5199\u5ba2\u6237\u7aef\u4ee3\u7801\u6765\u6d4b\u8bd5\u7b56\u7565\u6a21\u5f0f\u7684\u5b9e\u73b0\u3002<\/p>\n<pre>using system;\nusing system.data;\n\nnamespace myproject.util\n{\n    public class client\n    {\n        public static void main()\n        {\n            sqlstrategy sqlhelper = new(new tsqlquery());\n            datatable result = sqlhelper.getdatatable(\"select top (10) * from [product]\");\n\n            foreach (datarow row in result.rows)\n            {\n                foreach (datacolumn column in result.columns)\n                {\n                    console.write($\"{column.columnname}: {row[column]} \\t\");\n                }\n                console.writeline();\n            }\n        }\n    }\n}\n<\/pre>\n<p><strong>\u603b\u7ed3<\/strong><\/p>\n<ul>\n<li>\u5b9a\u4e49\u7b56\u7565\u63a5\u53e3\uff1a\u4f7f\u7528 getdatatable \u65b9\u6cd5\u521b\u5efa\u63a5\u53e3 isqlstrategy\u3002<\/li>\n<li>\u5b9e\u65bd\u5177\u4f53\u7b56\u7565\uff1a\u5b9e\u73b0 mysql\u3001postgresql \u548c sql server \u7684\u63a5\u53e3\u3002<\/li>\n<li>\u521b\u5efacontext\u7c7b\uff1a\u4f7f\u7528sqlstrategy\u7c7b\u4e0e\u7b56\u7565\u4ea4\u4e92\u3002<\/li>\n<li>\u7f16\u5199\u5ba2\u6237\u7aef\u4ee3\u7801\uff1a\u901a\u8fc7\u67e5\u8be2\u6570\u636e\u5e93\u6765\u6d4b\u8bd5\u5b9e\u73b0\u3002<\/li>\n<li>\u8fd9\u79cd\u65b9\u6cd5\u53ef\u4ee5\u8ba9\u60a8\u8f7b\u677e\u5730\u5728\u4e0d\u540c\u7684\u6570\u636e\u5e93\u5b9e\u73b0\u4e4b\u95f4\u5207\u6362\uff01<\/li>\n<\/ul>\n<p><strong>\u5b8c\u6574\u7f16\u7801<\/strong><\/p>\n<pre>using System;\nusing System.Configuration;\nusing System.Data;\nusing System.Data.SqlClient;\nusing Npgsql;\nusing MySql.Data.MySqlClient;\n\nnamespace MyProject.Util\n{\n    \/\/Strategy (Interface)\n    public interface ISQLStrategy\n    {\n        DataTable GetDataTable(string sql);\n\n        \/\/You could add more methods for \"Create\", \"Update\" as well\n    }\n\n    \/\/Concrete Strategies\n    public class MySQLQuery : ISQLStrategy\n    {\n        public DataTable GetDataTable(string sql)\n        {\n            try\n            {\n                using (MySqlConnection conn = new MySqlConnection(ConfigurationManager.AppSettings[\"MySqlConnectionString\"]))\n                {\n                    DataTable dt = new DataTable();\n\n                    conn.Open();\n\n                    MySqlCommand command = new MySqlCommand(sql, conn);\n\n                    dt.Load(command.ExecuteReader());\n\n                    conn.Close();\n\n                    return dt;\n                }\n            }\n            catch (Exception e)\n            {\n                Console.WriteLine(e.ToString());\n\n                return null;\n            }\n        }\n    }\n\n    public class NpgSqlQuery : ISQLStrategy\n    {\n        public DataTable GetDataTable(string sql)\n        {\n            try\n            {\n                using (NpgsqlConnection conn = new NpgsqlConnection(ConfigurationManager.AppSettings[\"NpgSqlConnectionString\"]))\n                {\n                    DataTable dt = new DataTable();\n\n                    conn.Open();\n\n                    NpgsqlCommand command = new NpgsqlCommand(sql, conn);\n\n                    NpgsqlDataAdapter _dap = new NpgsqlDataAdapter(command);\n\n                    _dap.Fill(dt);\n\n                    conn.Close();\n\n                    return dt;\n                }\n            }\n            catch (Exception e)\n            {\n                Console.WriteLine(e.ToString());\n\n                return null;\n            }\n        }\n    }\n\n    public class TSqlQuery : ISQLStrategy\n    {\n        public DataTable GetDataTable(string sql)\n        {\n            try\n            {\n                using (SqlConnection conn = new SqlConnection(ConfigurationManager.AppSettings[\"TSqlConnectionString\"]))\n                {\n                    DataTable dt = new DataTable();\n\n                    conn.Open();\n\n                    SqlCommand command = new SqlCommand(sql, conn);\n\n                    SqlDataAdapter da = new SqlDataAdapter(command);\n\n                    da.Fill(dt);\n\n                    conn.Close();\n\n                    return dt;\n                }\n            }\n            catch (Exception e)\n            {\n                Console.WriteLine(e.ToString());\n\n                return null;\n            }\n        }\n    }\n\n    \/\/Context\n    public class SQLStrategy\n    {\n        public ISQLStrategy _sqlStrategy;\n\n        public SQLStrategy(ISQLStrategy sqlStrategy)\n        {\n            _sqlStrategy = sqlStrategy;\n        }\n\n        public DataTable GetDataTable(string sql)\n        {\n            return _sqlStrategy.GetDataTable(sql);\n        }\n    }\n\n    \/\/ Testing the Strategy Design Pattern\n    \/\/ Client Code\n    public class Client\n    {\n        public static void Main()\n        {\n            SQLStrategy sqlHelper = new(new TSqlQuery());\n\n            DataTable result = sqlHelper.GetDataTable(\"SELECT TOP (10) * FROM [Product]\");\n\n            foreach (DataRow row in result.Rows)\n            {\n                foreach (DataColumn column in result.Columns)\n                {\n                    Console.Write($\"{column.ColumnName}: {row[column]} \\t\");\n                }\n\n                Console.WriteLine();\n            }\n        }\n    }\n}\n\n<\/pre>\n<blockquote>\n<p>\u70ed\u7231 c#\uff01<\/p>\n<\/blockquote>\n<p>\u4ee5\u4e0a\u5c31\u662f\u672c\u6587\u7684\u5168\u90e8\u5185\u5bb9\u4e86\uff0c\u662f\u5426\u6709\u987a\u5229\u5e2e\u52a9\u4f60\u89e3\u51b3\u95ee\u9898\uff1f\u82e5\u662f\u80fd\u7ed9\u4f60\u5e26\u6765\u5b66\u4e60\u4e0a\u7684\u5e2e\u52a9\uff0c\u8bf7\u5927\u5bb6\u591a\u591a\u652f\u6301\u4e3b\u673a\u5b9d\u8d1d\uff01\u66f4\u591a\u5173\u4e8e\u6570\u636e\u5e93\u7684\u76f8\u5173\u77e5\u8bc6\uff0c\u4e5f\u53ef\u5173\u6ce8\u4e3b\u673a\u5b9d\u8d1d\u516c\u4f17\u53f7\u3002<\/p>\n<p> \u7248\u672c\u58f0\u660e \u672c\u6587\u8f6c\u8f7d\u4e8e\uff1adev.to \u5982\u6709\u4fb5\u72af\uff0c\u8bf7\u8054\u7cfb \u5220\u9664 <\/p>\n<dl>\n<dt>\n <\/dt>\n<\/dl>\n","protected":false},"excerpt":{"rendered":"<p>\u4f7f\u7528\u7b56\u7565\u8bbe\u8ba1\u6a21\u5f0f\u5206\u6b65\u6307\u5357\u5728 C#&#46;&#46;&#46;<\/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-200702","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/200702","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=200702"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/200702\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=200702"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=200702"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=200702"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}