myormframework.cs

一个快速的数据库访问框架。可根据需要灵活的扩展。

				throw new ArgumentNullException("ObjectType");
			}
			this.CheckBindInfo( ObjectType , false );
			TableBindInfo table = this.GetBindInfo( ObjectType );
			string strSQL = "Select " + table.FieldNameList + " From " + FixTableName( table.TableName );
			return ReadObjects( strSQL , ObjectType , 0 );
		}

		/// <summary>
		/// 使用指定的SQL查询语句查询数据并读取一条数据库记录对象
		/// </summary>
		/// <param name="strSQL">SQL查询语句</param>
		/// <param name="ObjectType">要读取的对象类型</param>
		/// <returns>读取的对象</returns>
		public object ReadObject( string strSQL , Type ObjectType )
		{
			// 检查参数
			if( strSQL == null )
			{
				throw new ArgumentNullException("strSQL");
			}
			if( ObjectType == null )
			{
				throw new ArgumentNullException("ObjectType");
			}
			this.CheckBindInfo( ObjectType , false );
			object[] objs = ReadObjects( strSQL , ObjectType , 1 );
			if( objs != null && objs.Length == 1 )
				return objs[ 0 ] ;
			else
				return null;
		}

		/// <summary>
		/// 使用指定的SQL查询语句查询数据库并读取多条数据库记录对象
		/// </summary>
		/// <param name="strSQL">SQL查询语句</param>
		/// <param name="ObjectType">要读取的对象类型</param>
		/// <returns>读取的对象组成的数组</returns>
		public object[] ReadObjects( string strSQL , Type ObjectType)
		{
			if( ObjectType == null )
			{
				throw new ArgumentNullException("ObjectType");
			}
			// 检查数据库映射信息
			this.CheckBindInfo( ObjectType , false );
			return ReadObjects( strSQL , ObjectType , 0 );
		}

		/// <summary>
		/// 使用指定的SQL查询语句查询数据库并读取多条数据库记录对象
		/// </summary>
		/// <param name="strSQL">SQL查询语句</param>
		/// <param name="ObjectType">要读取的对象类型</param>
		/// <param name="MaxObjectCount">最多读取的对象个数</param>
		/// <returns>读取的对象组成的数组</returns>
		public object[] ReadObjects( string strSQL , Type ObjectType , int MaxObjectCount )
		{
			// 检查参数
			if( strSQL == null )
			{
				throw new ArgumentNullException("strSQL");
			}
			if( ObjectType == null )
			{
				throw new ArgumentNullException("ObjectType");
			}
			// 检查数据库映射信息
			this.CheckBindInfo( ObjectType , false );
			// 检查数据库连接
			this.CheckConnetion();
			// 创建SQL命令对象
			using( System.Data.IDbCommand cmd = myConnection.CreateCommand())
			{
				// 执行SQL查询,获得一个数据读取器
				cmd.CommandText = strSQL ;
				System.Data.IDataReader reader = cmd.ExecuteReader(
					MaxObjectCount == 1 ?
					System.Data.CommandBehavior.SingleRow : 
					System.Data.CommandBehavior.SingleResult );

				System.Collections.ArrayList list = new System.Collections.ArrayList();
				TableBindInfo table = this.GetBindInfo( ObjectType );
				lock( table )
				{
					// 设置字段序号，提高性能
					foreach( FieldBindInfo field in table.Fields )
					{
						field.FieldIndex = - 1 ;
					}
					for( int iCount = 0 ; iCount < reader.FieldCount ; iCount ++ )
					{
						string name = reader.GetName( iCount );
						foreach( FieldBindInfo field in table.Fields )
						{
							if( EqualsFieldName( name , field.FieldName ))
							{
								field.FieldIndex = iCount ;
							}
						}
					}
					while( reader.Read())
					{
						// 根据对象类型创建对象实例
						object obj = System.Activator.CreateInstance( ObjectType );
						// 读取对象属性值
						if( InnerReadValues( obj , table , reader ) > 0 )
						{
							list.Add( obj );
						}
						if( MaxObjectCount > 0 || list.Count == MaxObjectCount )
						{
							break;
						}
					}//while
				}//lock
				reader.Close();
				// 返回读取的对象数组
				return list.ToArray();
			}//using
		}

		#endregion

		#region  插入数据库记录的接口 *****************************************

		/// <summary>
		/// 将一个对象插入到数据库中
		/// </summary>
		/// <param name="obj">对象</param>
		/// <returns>插入的数据库记录个数</returns>
		public int InsertObject( object obj )
		{
			if( obj == null )
			{
				throw new ArgumentNullException("obj");
			}
			this.CheckBindInfo( obj.GetType() ,false );
			return InsertObject( obj , null );
		}

		/// <summary>
		/// 将一个对象插入到指定的数据表中
		/// </summary>
		/// <param name="obj">对象</param>
		/// <param name="TableName">指定的数据表，若未指定则为默认数据表名</param>
		/// <returns>插入的数据库记录的个数</returns>
		public int InsertObject( object obj , string TableName )
		{
			if( obj == null )
			{
				throw new ArgumentNullException("obj");
			}
			this.CheckBindInfo( obj.GetType() , false );
			return InsertObjects( new object[]{ obj } , TableName );
		}

		/// <summary>
		/// 将若干个对象插入到数据库中
		/// </summary>
		/// <param name="Objects">对象列表</param>
		/// <param name="TableName">制定的数据表，若未指定则使用默认的数据表名</param>
		/// <returns>插入的数据库记录的个数</returns>
		public int InsertObjects( System.Collections.IEnumerable Objects , string TableName )
		{
			if( Objects == null )
			{
				throw new ArgumentNullException("Objects");
			}
			this.CheckBindInfo( Objects , false );
			System.Collections.ArrayList list = new System.Collections.ArrayList();
			foreach( object obj in Objects )
			{
				list.Add( obj );
			}
			if( list.Count == 0 )
			{
				return 0 ;
			}
			this.CheckConnetion();
			// 上一次执行的SQL语句
			string strLastSQL = null ;
			int InsertCount = 0 ;
			using( System.Data.IDbCommand cmd = myConnection.CreateCommand())
			{
				foreach( object obj in list )
				{
					TableBindInfo table = this.GetBindInfo( obj.GetType());
					string TableName2 = TableName ;
					if( TableName2 == null || TableName.Trim().Length == 0 )
					{
						TableName2 = table.TableName ;
					}
					System.Collections.ArrayList values = new System.Collections.ArrayList();
					// 拼凑SQL语句
					System.Text.StringBuilder myStr = new System.Text.StringBuilder();
					System.Text.StringBuilder myFields = new System.Text.StringBuilder();
					foreach( FieldBindInfo field in table.Fields )
					{
						if( field.Property.CanRead == false )
						{
							throw new Exception("属性 " + field.Property.Name + " 是不可写的");
						}
						object v = field.Property.GetValue( obj , null );
						if( v == null || DBNull.Value.Equals( v ))
						{
							continue ;
						}
						values.Add( field.ToDataBase( v ));
						if( myStr.Length > 0 )
						{
							myStr.Append(" , ");
							myFields.Append( " , " );
						}

						myStr.Append(" ? " );
						myFields.Append( FixFieldName( field.FieldName ));

					}//foreach
					myStr.Insert( 0 , "Insert Into " + FixTableName( TableName2 ) 
						+  " ( " + myFields.ToString() + " ) Values ( " );
					myStr.Append( " ) " );
					string strSQL = myStr.ToString();

					if( strSQL != strLastSQL )
					{
						// 重新设置SQL命令对象
						strLastSQL = strSQL ;
						cmd.Parameters.Clear();
						cmd.CommandText = strSQL ;
						for( int iCount = 0 ; iCount < values.Count ; iCount ++ )
						{
							cmd.Parameters.Add( cmd.CreateParameter());
						}
					}

					// 填充SQL命令参数值
					for( int iCount = 0 ; iCount < values.Count ; iCount ++ )
					{
						( ( System.Data.IDbDataParameter ) cmd.Parameters[ iCount ]).Value = values[ iCount ] ;
					}

					// 执行SQL命令向数据表新增记录
					InsertCount += cmd.ExecuteNonQuery();
				}//foreach
			}//using
			return InsertCount ;
		}

		#endregion

		/// <summary>
		/// 修正数据表名
		/// </summary>
		/// <param name="TableName">旧的数据表名</param>
		/// <returns>修正后的数据表名</returns>
		/// <remarks>
		/// 在某些情况下，程序指定的数据表名是不合法的，需要对其进行修正。比如对于Access则在表的两边加上方括号。
		/// </remarks>
		protected virtual string FixTableName( string TableName )
		{
			return TableName ;
		}

		/// <summary>
		/// 修正数据字段名
		/// </summary>
		/// <param name="FieldName">旧的数据字段名</param>
		/// <returns>修正后的字段名</returns>
		/// <remarks>
		/// 在某些情况下，程序指定的字段名不合法，需要对其进行修正，比如对于Access则在表的两边加上方括号。
		/// </remarks>
		protected virtual string FixFieldName( string FieldName )
		{
			return FieldName ;
		}
		
		/// <summary>
		/// 销毁对象
		/// </summary>
		public void Dispose()
		{
			if( myConnection != null )
			{
				if( myConnection.State == System.Data.ConnectionState.Open )
				{
					myConnection.Close();
				}
				myConnection = null ;
			}
		}

		#region 内部私有成员 **************************************************

		/// <summary>
		/// 检查数据库连接是否可用
		/// </summary>
		private void CheckConnetion()
		{
			if( myConnection == null || myConnection.State != System.Data.ConnectionState.Open )
			{
				throw new InvalidOperationException("数据库连接无效");
			}
		}
		
		/// <summary>
		/// 根据对象数值创建查询条件子SQL语句
		/// </summary>
		/// <param name="obj">对象</param>
		/// <param name="values">SQL参数值列表</param>
		/// <returns>创建的SQL语句字符串</returns>
		private string BuildCondition( object obj , System.Collections.ArrayList values )
		{
			TableBindInfo table = this.GetBindInfo( obj.GetType() );
			// 拼凑查询条件SQL语句
			System.Text.StringBuilder mySQL = new System.Text.StringBuilder();
			foreach( FieldBindInfo field in table.Fields )
			{
				if( field.Attribute.Key )
				{
					object v = field.Property.GetValue( obj , null );
					if( v == null || DBNull.Value.Equals( v ))
					{
						throw new Exception("关键字段属性 " + field.Property.Name + " 未指定值" ) ;
					}
					if( mySQL.Length > 0 )
					{
						mySQL.Append(" And " );
					}
					mySQL.Append( FixFieldName( field.FieldName ));
					mySQL.Append( " = ? " );
					values.Add( field.ToDataBase( v ));
				}
			}//foreach
			if( mySQL.Length == 0 )
			{
				throw new Exception("类型 " + obj.GetType().FullName + " 未能生成查询条件");
			}
			return mySQL.ToString();
		}

		/// <summary>
		/// 从数据读取器中读取数据并填充到一个对象中
		/// </summary>
		/// <param name="ObjInstance">对象实例</param>
		/// <param name="info">数据库绑定信息对象</param>
		/// <param name="reader">数据读取器</param>
		private int InnerReadValues( object ObjInstance , TableBindInfo info , System.Data.IDataReader reader )
		{
			// 检查参数
			if( ObjInstance == null )
			{
				throw new ArgumentNullException("ObjectInstance");
			}
			if( info == null )
			{
				throw new ArgumentNullException("info");
			}
			if( reader == null )
			{
				throw new ArgumentNullException("reader");
			}
			int FieldCount = 0 ;
			// 依次读取各个属性值
			foreach( FieldBindInfo field in info.Fields )
			{
				// 绑定的属性是只读的
				if( field.Property.CanWrite == false )
				{
					continue ;
				}
				// 没有找到绑定的字段
				if( field.FieldIndex < 0 )
				{
					continue ;
				}