1 /// <summary> 2 /// 执行Sql语句 3 /// </summary> 4 public static class DatabaseExtend 5 { 6 /// <summary> 7 /// 执行任何SQL语句,通用所有的数据库(SQLServer,MySql,Oracle等),利用EMIT快速反射,得到动态类型实体,支持参数查询,防止sql注入。 Created by ZhangQC 8 /// </summary> 9 /// <param name="db">数据库操作</param> 10 /// <param name="sql">执行的sql命令</param> 11 /// <param name="parameters">参数</param> 12 /// <param name="serverName">sql服务提供者</param> 13 /// <returns></returns> 14 public static IEnumerable SqlQueryForDynamic(this Database db, string sql, SystemEnum.DataProvider serverName = SystemEnum.DataProvider.MySql, params object[] parameters) 15 { 16 //获取数据库连接提供者 17 IDbConnection defaultConn = GetConnection(serverName); 18 return SqlQueryForDynamicOtherDb(db, sql, defaultConn, parameters); 19 } 20 21 public static IEnumerable<T> SqlQueryForSpecificType<T>(this Database db, string sql,SqlParameter[] parameters, 22 SystemEnum.DataProvider serverName = SystemEnum.DataProvider.SqlServer) 23 { 24 //获取数据库连接提供者 25 IDbConnection defaultConn = GetConnection(serverName); 26 return SqlQueryForSpecificTypeOtherDb<T>(db, sql, defaultConn, parameters); 27 } 28 29 30 31 /// <summary> 32 /// 获取连接字符串 Created by ZhangQC 33 /// </summary> 34 /// <param name="providerType"></param> 35 /// <returns></returns> 36 public static IDbConnection GetConnection(SystemEnum.DataProvider providerType) 37 { 38 IDbConnection iDbConnection; 39 switch (providerType) 40 { 41 case SystemEnum.DataProvider.SqlServer: 42 iDbConnection = new SqlConnection(); 43 break; 44 case SystemEnum.DataProvider.OleDb: 45 iDbConnection = new OleDbConnection(); 46 break; 47 case SystemEnum.DataProvider.Odbc: 48 iDbConnection = new OdbcConnection(); 49 break; 50 case SystemEnum.DataProvider.Oracle: 51 //iDbConnection = new OracleConnection(); 52 iDbConnection = new SqlConnection(); 53 break; 54 case SystemEnum.DataProvider.MySql: 55 //iDbConnection = new MySqlConnection(); 56 iDbConnection = new SqlConnection(); 57 break; 58 default: 59 return null; 60 } 61 return iDbConnection; 62 } 63 64 /// <summary> 65 /// 执行sql语句,要求提供接受实体 66 /// </summary> 67 /// <typeparam name="T"></typeparam> 68 /// <param name="db"></param> 69 /// <param name="sql"></param> 70 /// <param name="conn"></param> 71 /// <param name="parameters"></param> 72 /// <returns></returns> 73 public static IEnumerable<T> SqlQueryForSpecificTypeOtherDb<T>(this Database db, string sql, IDbConnection conn, 74 object[] parameters) 75 { 76 if (parameters != null) 77 { 78 return db.SqlQuery<T>(sql, parameters).Cast<T>().ToList(); 79 } 80 return db.SqlQuery<T>(sql).ToList(); 81 } 82 83 84 85 86 /// <summary> 87 /// 使用反射发出(快速反射EMIT)动态创建返回 Created by ZhangQC 88 /// </summary> 89 /// <param name="db"></param> 90 /// <param name="sql"></param> 91 /// <param name="conn"></param> 92 /// <param name="parameters"></param> 93 /// <returns></returns> 94 public static IEnumerable SqlQueryForDynamicOtherDb(this Database db, string sql, IDbConnection conn, params object[] parameters) 95 { 96 conn.ConnectionString = db.Connection.ConnectionString; 97 98 if (conn.State != ConnectionState.Open) 99 { 100 conn.Open(); 101 } 102 103 IDbCommand cmd = conn.CreateCommand(); 104 105 cmd.CommandText = sql; 106 //开启防止SQL注入,这里万分重要啊 ZhangqC 107 if (parameters != null) 108 { 109 foreach (var obj in parameters) 110 { 111 cmd.Parameters.Add(obj); 112 } 113 } 114 115 IDataReader dataReader = cmd.ExecuteReader(); 116 117 if (!dataReader.Read()) 118 { 119 return null; //无结果返回Null 120 } 121 122 #region 构建动态字段 123 124 TypeBuilder builder = CreateTypeBuilder("EF_DynamicModelAssembly", "DynamicModule", "DynamicType"); 125 126 int fieldCount = dataReader.FieldCount; 127 for (int i = 0; i < fieldCount; i++) 128 { 129 //此处类型需要特殊处理(比较尴尬,需要优化) 130 if (dataReader.GetFieldType(i) == typeof(decimal)) 131 { 132 CreateAutoImplementedProperty(builder, dataReader.GetName(i), typeof(decimal?)); 133 } 134 else if (dataReader.GetFieldType(i) == typeof(DateTime)) 135 { 136 CreateAutoImplementedProperty(builder, dataReader.GetName(i), typeof(DateTime?)); 137 } 138 else if (dataReader.GetFieldType(i) == typeof(int)) 139 { 140 CreateAutoImplementedProperty(builder, dataReader.GetName(i), typeof(int?)); 141 } 142 else 143 { 144 CreateAutoImplementedProperty(builder, dataReader.GetName(i), dataReader.GetFieldType(i)); 145 } 146 } 147 148 #endregion 149 150 dataReader.Close(); 151 dataReader.Dispose(); 152 cmd.Dispose(); 153 conn.Close(); 154 conn.Dispose(); 155 156 Type returnType = builder.CreateType(); 157 158 if (parameters != null) 159 { 160 var result= db.SqlQuery(returnType, sql, parameters); 161 //解决循环调用的报错问题 162 cmd.Parameters.Clear(); 163 return result; 164 } 165 else 166 { 167 return db.SqlQuery(returnType, sql); 168 } 169 } 170 171 /// <summary> 172 /// 动态创建程序集 ZhangQC 173 /// </summary> 174 /// <param name="assemblyName"></param> 175 /// <param name="moduleName"></param> 176 /// <param name="typeName"></param> 177 /// <returns></returns> 178 public static TypeBuilder CreateTypeBuilder(string assemblyName, string moduleName, string typeName) 179 { 180 TypeBuilder typeBuilder = AppDomain.CurrentDomain.DefineDynamicAssembly( 181 new AssemblyName(assemblyName), 182 AssemblyBuilderAccess.Run).DefineDynamicModule(moduleName).DefineType(typeName, 183 TypeAttributes.Public); 184 typeBuilder.DefineDefaultConstructor(MethodAttributes.Public); 185 return typeBuilder; 186 } 187 188 189 /// <summary> 190 /// 动态创建实体 ZhangQC 191 /// </summary> 192 /// <param name="builder"></param> 193 /// <param name="propertyName"></param> 194 /// <param name="propertyType"></param> 195 public static void CreateAutoImplementedProperty(TypeBuilder builder, string propertyName, Type propertyType) 196 { 197 const string privateFieldPrefix = "m_"; 198 const string getterPrefix = "get_"; 199 const string setterPrefix = "set_"; 200 201 202 203 // Generate the field. 204 FieldBuilder fieldBuilder = builder.DefineField( 205 string.Concat( 206 privateFieldPrefix, propertyName), 207 propertyType, 208 FieldAttributes.Private); 209 210 // Generate the property 211 PropertyBuilder propertyBuilder = builder.DefineProperty( 212 propertyName, 213 System.Reflection.PropertyAttributes.HasDefault, 214 propertyType, null); 215 216 // Property getter and setter attributes. 217 MethodAttributes propertyMethodAttributes = MethodAttributes.Public 218 | MethodAttributes.SpecialName 219 | MethodAttributes.HideBySig; 220 221 // Define the getter method. 222 MethodBuilder getterMethod = builder.DefineMethod( 223 string.Concat( 224 getterPrefix, propertyName), 225 propertyMethodAttributes, 226 propertyType, 227 Type.EmptyTypes); 228 229 // Emit the IL code. 230 // ldarg.0 231 // ldfld,_field 232 // ret 233 ILGenerator getterIlCode = getterMethod.GetILGenerator(); 234 getterIlCode.Emit(OpCodes.Ldarg_0); 235 getterIlCode.Emit(OpCodes.Ldfld, fieldBuilder); 236 getterIlCode.Emit(OpCodes.Ret); 237 238 // Define the setter method. 239 MethodBuilder setterMethod = builder.DefineMethod( 240 string.Concat(setterPrefix, propertyName), 241 propertyMethodAttributes, 242 null, 243 new Type[] { propertyType }); 244 245 // Emit the IL code. 246 // ldarg.0 247 // ldarg.1 248 // stfld,_field 249 // ret 250 ILGenerator setterIlCode = setterMethod.GetILGenerator(); 251 setterIlCode.Emit(OpCodes.Ldarg_0); 252 setterIlCode.Emit(OpCodes.Ldarg_1); 253 setterIlCode.Emit(OpCodes.Stfld, fieldBuilder); 254 setterIlCode.Emit(OpCodes.Ret); 255 256 propertyBuilder.SetGetMethod(getterMethod); 257 propertyBuilder.SetSetMethod(setterMethod); 258 } 259 }
时间: 2024-10-14 00:35:34