执行Sql语句，包括存储过程，可以动态生成返回实体

Posted 2020-08-28 小小的菜鸟程序员

  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 }