对数据库操作类的封装

      Enterprise Library 2.0很多人都已熟悉，有的人也在很多项目里做了应用，
很早以前也使用企业库的2.0做了一些项目，但感觉很多代码还是有些冗余和重复，
同时为了兼容现有的系统结构而不影响现有数据访问方式（包括 代码生成器的DAL代码）不变，
对Enterprise Library 2.0 的调用进行了进一步封装(按我过去 DbHelperSQL的思路)，在不改变现有的DAL的方式下来使用企业库。
当然，你完全可以直接使用企业库做一些更灵活的应用，这里只是抛砖引玉的一个解决方案。

  /**/ /// <summary>

    /// Enterprise Library 2.0 数据访问进一步封装类

     /// Copyright (C) 2006-2008 LiTianPing

     /// All rights reserved 

     /// </summary>

      public   abstract   class  DbHelperSQL2

      ... {        

         public DbHelperSQL2()

         ...{

        }

 

        公用方法#region 公用方法

        /**//// <summary>

        /// 获取表某个字段的最大值

        /// </summary>

        /// <param name="FieldName"></param>

        /// <param name="TableName"></param>

        /// <returns></returns>

        public static int GetMaxID(string FieldName,string TableName)

        ...{

            string strSql = "select max(" + FieldName + ")+1 from " + TableName;

            Database db = DatabaseFactory.CreateDatabase();

            DbCommand dbCommand = db.GetSqlStringCommand(strSql);           

            object obj = db.ExecuteScalar(dbCommand);

            if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))

            ...{

                return 1;

            }

            else

            ...{

                return int.Parse(obj.ToString());

            }           

        }

        /**//// <summary>

        /// 检测一个记录是否存在(SQL语句方式)

        /// </summary>

        /// <param name="strSql"></param>

        /// <returns></returns>

         public static bool Exists(string strSql)

         ...{

            Database db = DatabaseFactory.CreateDatabase();

            DbCommand dbCommand = db.GetSqlStringCommand(strSql);

            object obj = db.ExecuteScalar(dbCommand);

              int cmdresult;

              if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))

              ...{

                   cmdresult = 0;

              }

              else

              ...{

                   cmdresult = int.Parse(obj.ToString());

              }

              if (cmdresult == 0)

              ...{

                   return false;

              }

              else

              ...{

                   return true;

              }

         }

        /**//// <summary>

        ///  检测一个记录是否存在(SqlParameter语句方式)

        /// </summary>

        /// <param name="strSql"></param>

        /// <param name="cmdParms"></param>

        /// <returns></returns>

        public static bool Exists(string strSql, params SqlParameter[] cmdParms)

        ...{

            Database db = DatabaseFactory.CreateDatabase();

            DbCommand dbCommand = db.GetSqlStringCommand(strSql);

            BuildDBParameter(db, dbCommand, cmdParms);            

            object obj = db.ExecuteScalar(dbCommand);           

            int cmdresult;

            if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))

            ...{

                cmdresult = 0;

            }

            else

            ...{

                cmdresult = int.Parse(obj.ToString());

            }

            if (cmdresult == 0)

            ...{

                return false;

            }

            else

            ...{

                return true;

            }

        }

        

        /**//// <summary>

        /// 加载参数

        /// </summary>

        public static void BuildDBParameter(Database db, DbCommand dbCommand, params SqlParameter[] cmdParms)

        ...{

            foreach (SqlParameter sp in cmdParms)

            ...{

                db.AddInParameter(dbCommand, sp.ParameterName, sp.DbType,sp.Value);

            }

        }

        #endregion

 

        执行简单SQL语句#region  执行简单SQL语句

 

        /**//// <summary>

         /// 执行SQL语句，返回影响的记录数

         /// </summary>

         /// <param name="strSql">SQL语句</param>

         /// <returns>影响的记录数</returns>

        public static int ExecuteSql(string strSql)

         ...{    

            Database db = DatabaseFactory.CreateDatabase();

            DbCommand dbCommand = db.GetSqlStringCommand(strSql);

            return db.ExecuteNonQuery(dbCommand);

         }

        /**//// <summary>

        /// 执行SQL语句，返回影响的记录数(对于长时间查询的语句，设置等待时间避免查询超时)

        /// </summary>

        /// <param name="strSql"></param>

        /// <param name="Times"></param>

        /// <returns></returns>

         public static int ExecuteSqlByTime(string strSql,int Times)

         ...{           

            Database db = DatabaseFactory.CreateDatabase();

            DbCommand dbCommand = db.GetSqlStringCommand(strSql);

            dbCommand.CommandTimeout = Times;

            return db.ExecuteNonQuery(dbCommand);

         }

         

         /**//// <summary>

         /// 执行多条SQL语句，实现数据库事务。

         /// </summary>

         /// <param name="SQLStringList">多条SQL语句</param>     

         public static void ExecuteSqlTran(ArrayList SQLStringList)

         ...{

 

            Database db = DatabaseFactory.CreateDatabase();

            using (DbConnection dbconn = db.CreateConnection())

            ...{ 

                dbconn.Open();

                DbTransaction dbtran = dbconn.BeginTransaction();

                try

                ...{

                    //执行语句

                    for (int n = 0; n < SQLStringList.Count; n++)

                    ...{

                        string strsql = SQLStringList[n].ToString();

                        if (strsql.Trim().Length > 1)

                        ...{

                            DbCommand dbCommand = db.GetSqlStringCommand(strsql);

                            db.ExecuteNonQuery(dbCommand);

                        }

                    }

                    //执行存储过程

                    //db.ExecuteNonQuery(CommandType.StoredProcedure, "InserOrders");

                    //db.ExecuteDataSet(CommandType.StoredProcedure, "UpdateProducts");

                    dbtran.Commit();

                }

                catch

                ...{

                    dbtran.Rollback();

                }

                finally

                ...{

                    dbconn.Close();

                }

            }

        }

 

        执行一个特殊字段带参数的语句#region 执行一个特殊字段带参数的语句

        /**//// <summary>

         /// 执行带一个存储过程参数的的SQL语句。

         /// </summary>

         /// <param name="strSql">SQL语句</param>

         /// <param name="content">参数内容,比如一个字段是格式复杂的文章，有特殊符号，可以通过这个方式添加</param>

         /// <returns>影响的记录数</returns>

         public static int ExecuteSql(string strSql,string content)

         ...{    

            Database db = DatabaseFactory.CreateDatabase();

            DbCommand dbCommand = db.GetSqlStringCommand(strSql);

            db.AddInParameter(dbCommand, "@content", DbType.String, content);

            return db.ExecuteNonQuery(dbCommand);

         }        

         

        /**//// <summary>

         /// 执行带一个存储过程参数的的SQL语句。

         /// </summary>

         /// <param name="strSql">SQL语句</param>

         /// <param name="content">参数内容,比如一个字段是格式复杂的文章，有特殊符号，可以通过这个方式添加</param>

         /// <returns>返回语句里的查询结果</returns>

         public static object ExecuteSqlGet(string strSql,string content)

         ...{

            Database db = DatabaseFactory.CreateDatabase();

            DbCommand dbCommand = db.GetSqlStringCommand(strSql);

            db.AddInParameter(dbCommand, "@content", DbType.String, content);

            object obj = db.ExecuteNonQuery(dbCommand);

            if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))

            ...{

                return null;

            }

            else

            ...{

                return obj;

            }      

         }        

         

        /**//// <summary>

         /// 向数据库里插入图像格式的字段(和上面情况类似的另一种实例)

         /// </summary>

         /// <param name="strSql">SQL语句</param>

         /// <param name="fs">图像字节,数据库的字段类型为image的情况</param>

         /// <returns>影响的记录数</returns>

         public static int ExecuteSqlInsertImg(string strSql,byte[] fs)

         ...{

            Database db = DatabaseFactory.CreateDatabase();

            DbCommand dbCommand = db.GetSqlStringCommand(strSql);

            db.AddInParameter(dbCommand, "@fs", DbType.Byte, fs);

            return db.ExecuteNonQuery(dbCommand);            

        }

        #endregion

 

        /**//// <summary>

         /// 执行一条计算查询结果语句，返回查询结果（object）。

         /// </summary>

         /// <param name="strSql">计算查询结果语句</param>

         /// <returns>查询结果（object）</returns>

         public static object GetSingle(string strSql)

         ...{            

            Database db = DatabaseFactory.CreateDatabase();

            DbCommand dbCommand = db.GetSqlStringCommand(strSql);

            object obj = db.ExecuteScalar(dbCommand);

            if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))

            ...{

                return null;

            }

            else

            ...{

                return obj;

            }      

         }

         

        /**//// <summary>

        /// 执行查询语句，返回SqlDataReader ( 注意：使用后一定要对SqlDataReader进行Close )

         /// </summary>

         /// <param name="strSql">查询语句</param>

         /// <returns>SqlDataReader</returns>

        public static SqlDataReader ExecuteReader(string strSql)

         ...{

            Database db = DatabaseFactory.CreateDatabase();

            DbCommand dbCommand = db.GetSqlStringCommand(strSql);

            SqlDataReader dr = (SqlDataReader)db.ExecuteReader(dbCommand);

            return dr;      

              

         }        

         

        /**//// <summary>

         /// 执行查询语句，返回DataSet

         /// </summary>

         /// <param name="strSql">查询语句</param>

         /// <returns>DataSet</returns>

         public static DataSet Query(string strSql)

         ...{            

            Database db = DatabaseFactory.CreateDatabase();

            DbCommand dbCommand = db.GetSqlStringCommand(strSql);

            return db.ExecuteDataSet(dbCommand);

            

         }

        //(对于长时间查询的语句，设置等待时间避免查询超时)

         public static DataSet Query(string strSql,int Times)

         ...{

            Database db = DatabaseFactory.CreateDatabase();

            DbCommand dbCommand = db.GetSqlStringCommand(strSql);

            dbCommand.CommandTimeout = Times;

            return db.ExecuteDataSet(dbCommand);

         }

 

         #endregion

 

         执行带参数的SQL语句#region 执行带参数的SQL语句

 

         /**//// <summary>

         /// 执行SQL语句，返回影响的记录数

         /// </summary>

         /// <param name="strSql">SQL语句</param>

         /// <returns>影响的记录数</returns>

         public static int ExecuteSql(string strSql,params SqlParameter[] cmdParms)

         ...{

            Database db = DatabaseFactory.CreateDatabase();

            DbCommand dbCommand = db.GetSqlStringCommand(strSql);

            BuildDBParameter(db, dbCommand, cmdParms);    

            return db.ExecuteNonQuery(dbCommand);

         }

         

              

         /**//// <summary>

         /// 执行多条SQL语句，实现数据库事务。

         /// </summary>

         /// <param name="SQLStringList">SQL语句的哈希表（key为sql语句，value是该语句的SqlParameter[]）</param>

         public static void ExecuteSqlTran(Hashtable SQLStringList)

         ...{

            Database db = DatabaseFactory.CreateDatabase();

            using (DbConnection dbconn = db.CreateConnection())

            ...{

                dbconn.Open();

                DbTransaction dbtran = dbconn.BeginTransaction();

                try

                ...{

                    //执行语句

                    foreach (DictionaryEntry myDE in SQLStringList)

                    ...{

                        string strsql = myDE.Key.ToString();

                        SqlParameter[] cmdParms = (SqlParameter[])myDE.Value;                        

                        if (strsql.Trim().Length > 1)

                        ...{

                            DbCommand dbCommand = db.GetSqlStringCommand(strsql);

                            BuildDBParameter(db, dbCommand, cmdParms);    

                            db.ExecuteNonQuery(dbCommand);

                        }

                    }

                    dbtran.Commit();

                }

                catch

                ...{

                    dbtran.Rollback();

                }

                finally

                ...{

                    dbconn.Close();

                }

            }

         }

     

                   

         /**//// <summary>

         /// 执行一条计算查询结果语句，返回查询结果（object）。

         /// </summary>

         /// <param name="strSql">计算查询结果语句</param>

         /// <returns>查询结果（object）</returns>

         public static object GetSingle(string strSql,params SqlParameter[] cmdParms)

         ...{

            Database db = DatabaseFactory.CreateDatabase();

            DbCommand dbCommand = db.GetSqlStringCommand(strSql);

            BuildDBParameter(db, dbCommand, cmdParms);    

            object obj = db.ExecuteScalar(dbCommand);

            if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value)))

            ...{

                return null;

            }

            else

            ...{

                return obj;

            }      

         }

         

         /**//// <summary>

        /// 执行查询语句，返回SqlDataReader ( 注意：使用后一定要对SqlDataReader进行Close )

         /// </summary>

         /// <param name="strSql">查询语句</param>

         /// <returns>SqlDataReader</returns>

         public static SqlDataReader ExecuteReader(string strSql,params SqlParameter[] cmdParms)

         ...{        

            Database db = DatabaseFactory.CreateDatabase();

            DbCommand dbCommand = db.GetSqlStringCommand(strSql);

            BuildDBParameter(db, dbCommand, cmdParms);

            SqlDataReader dr = (SqlDataReader)db.ExecuteReader(dbCommand);

            return dr;

              

         }        

         

         /**//// <summary>

         /// 执行查询语句，返回DataSet

         /// </summary>

         /// <param name="strSql">查询语句</param>

         /// <returns>DataSet</returns>

         public static DataSet Query(string strSql,params SqlParameter[] cmdParms)

         ...{

            Database db = DatabaseFactory.CreateDatabase();

            DbCommand dbCommand = db.GetSqlStringCommand(strSql);

            BuildDBParameter(db, dbCommand, cmdParms);   

            return db.ExecuteDataSet(dbCommand);

         }

 

 

         private static void PrepareCommand(SqlCommand cmd,SqlConnection conn,SqlTransaction trans, string cmdText, SqlParameter[] cmdParms) 

         ...{

              if (conn.State != ConnectionState.Open)

                   conn.Open();

              cmd.Connection = conn;

              cmd.CommandText = cmdText;

              if (trans != null)

                   cmd.Transaction = trans;

              cmd.CommandType = CommandType.Text;//cmdType;

              if (cmdParms != null) 

              ...{

                foreach (SqlParameter parameter in cmdParms)

                   ...{

                       if ( ( parameter.Direction == ParameterDirection.InputOutput || parameter.Direction == ParameterDirection.Input ) && 

                            (parameter.Value == null))

                       ...{

                            parameter.Value = DBNull.Value;

                       }

                       cmd.Parameters.Add(parameter);

                   }

              }

         }

 

         #endregion

 

         存储过程操作#region 存储过程操作

 

        /**//// <summary>

        /// 执行存储过程，返回影响的行数       

        /// </summary>       

        public static int RunProcedure(string storedProcName)

        ...{

            Database db = DatabaseFactory.CreateDatabase();

            DbCommand dbCommand = db.GetStoredProcCommand(storedProcName);

            return db.ExecuteNonQuery(dbCommand);

        }

 

        /**//// <summary>

        /// 执行存储过程，返回输出参数的值和影响的行数       

        /// </summary>

        /// <param name="storedProcName">存储过程名</param>

        /// <param name="parameters">存储过程参数</param>

        /// <param name="OutParameter">输出参数名称</param>

        /// <param name="rowsAffected">影响的行数</param>

        /// <returns></returns>

        public static object RunProcedure(string storedProcName, IDataParameter[] InParameters, SqlParameter OutParameter, int rowsAffected)

        ...{

            Database db = DatabaseFactory.CreateDatabase();

            DbCommand dbCommand = db.GetStoredProcCommand(storedProcName);

            BuildDBParameter(db, dbCommand, (SqlParameter[])InParameters);

            db.AddOutParameter(dbCommand, OutParameter.ParameterName, OutParameter.DbType, OutParameter.Size);

            rowsAffected = db.ExecuteNonQuery(dbCommand);

            return db.GetParameterValue(dbCommand,"@" + OutParameter.ParameterName);  //得到输出参数的值

        }

 

         /**//// <summary>

        /// 执行存储过程，返回SqlDataReader ( 注意：使用后一定要对SqlDataReader进行Close )

         /// </summary>

         /// <param name="storedProcName">存储过程名</param>

         /// <param name="parameters">存储过程参数</param>

         /// <returns>SqlDataReader</returns>

         public static SqlDataReader RunProcedure(string storedProcName, IDataParameter[] parameters )

         ...{

            Database db = DatabaseFactory.CreateDatabase();

            DbCommand dbCommand = db.GetStoredProcCommand(storedProcName, parameters);            

            //BuildDBParameter(db, dbCommand, parameters);

            return (SqlDataReader)db.ExecuteReader(dbCommand);           

         }

                   

         /**//// <summary>

        /// 执行存储过程，返回DataSet

         /// </summary>

         /// <param name="storedProcName">存储过程名</param>

         /// <param name="parameters">存储过程参数</param>

         /// <param name="tableName">DataSet结果中的表名</param>

         /// <returns>DataSet</returns>

         public static DataSet RunProcedure(string storedProcName, IDataParameter[] parameters, string tableName )

         ...{           

            Database db = DatabaseFactory.CreateDatabase();

            DbCommand dbCommand = db.GetStoredProcCommand(storedProcName, parameters);

            //BuildDBParameter(db, dbCommand, parameters);

            return db.ExecuteDataSet(dbCommand); 

         }

        /**//// <summary>

        /// 执行存储过程，返回DataSet(设定等待时间)

        /// </summary>

         public static DataSet RunProcedure(string storedProcName, IDataParameter[] parameters, string tableName ,int Times)

         ...{           

            Database db = DatabaseFactory.CreateDatabase();

            DbCommand dbCommand = db.GetStoredProcCommand(storedProcName, parameters);

            dbCommand.CommandTimeout = Times;

            //BuildDBParameter(db, dbCommand, parameters);

            return db.ExecuteDataSet(dbCommand); 

         }

 

         

         /**//// <summary>

         /// 构建SqlCommand 对象(用来返回一个结果集，而不是一个整数值)

         /// </summary>

         /// <param name="connection">数据库连接</param>

         /// <param name="storedProcName">存储过程名</param>

         /// <param name="parameters">存储过程参数</param>

         /// <returns>SqlCommand</returns>

         private static SqlCommand BuildQueryCommand(SqlConnection connection,string storedProcName, IDataParameter[] parameters)

         ...{             

              SqlCommand command = new SqlCommand( storedProcName, connection );

              command.CommandType = CommandType.StoredProcedure;

              foreach (SqlParameter parameter in parameters)

              ...{

                   if( parameter != null )

                   ...{

                       // 检查未分配值的输出参数,将其分配以DBNull.Value.

                       if ( ( parameter.Direction == ParameterDirection.InputOutput || parameter.Direction == ParameterDirection.Input ) && 

                            (parameter.Value == null))

                       ...{

                            parameter.Value = DBNull.Value;

                       }

                       command.Parameters.Add(parameter);

                   }

              }             

              return command;             

         }        

         /**//// <summary>

         /// 创建SqlCommand 对象实例(用来返回一个整数值)    

         /// </summary>

         /// <param name="storedProcName">存储过程名</param>

         /// <param name="parameters">存储过程参数</param>

         /// <returns>SqlCommand 对象实例</returns>

         private static SqlCommand BuildIntCommand(SqlConnection connection,string storedProcName, IDataParameter[] parameters)

         ...{

              SqlCommand command = BuildQueryCommand(connection,storedProcName, parameters );

              command.Parameters.Add( new SqlParameter ( "ReturnValue",

                   SqlDbType.Int,4,ParameterDirection.ReturnValue,

                   false,0,0,string.Empty,DataRowVersion.Default,null ));

              return command;

         }

         #endregion    
     }

 对使用现有 Codematic代码生成的用户想使用企业库的话，可以直接替换此类。
同时,对于直接对企业库的DAL代码生成，希望在以后有时间会加进去，以方便大家不同方式的开发。