C# ACCESS数据库操作类

using System; using System.Text; using System.Collections; using System.Collections.Specialized; using System.Data; using System.Data.OleDb; using System.Configuration; namespace HoverTree.Web.DBUtility { /// <summary> /// 数据访问抽象基础类(ACCESS) /// Copyright (C) 2006-2007 hovertree.net /// All rights reserved /// </summary> public abstract class DbHelperACE { //数据库连接字符串(web.config来配置) //public static string connectionString = ConfigurationManager.AppSettings["ConnectionString"]; // public static string connectionString = System.Web.HttpContext.Current.Server.MapPath(ConfigurationManager.AppSettings["AccessConnectionString"]);  public static string connectionString = ConfigurationManager.AppSettings["AccessConnectionString"]; public DbHelperACE() { } #region 公用方法 public static int GetMaxID(string FieldName, string TableName) { string strsql = "select max(" + FieldName + ")+1 from " + TableName; object obj = DbHelperACE.GetSingle(strsql); if (obj == null) { return 1; } else { return int.Parse(obj.ToString()); } } public static bool Exists(string strSql) { object obj = DbHelperACE.GetSingle(strSql); 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; } } public static bool Exists(string strSql, params OleDbParameter[] cmdParms) { object obj = DbHelperACE.GetSingle(strSql, cmdParms); 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; } } #endregion #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="SQLString">SQL语句</param> /// <returns>影响的记录数</returns> public static int ExecuteSql(string SQLString) { using (OleDbConnection connection = new OleDbConnection(connectionString)) { using (OleDbCommand cmd = new OleDbCommand(SQLString, connection)) { try { connection.Open(); int rows = cmd.ExecuteNonQuery(); return rows; } catch (System.Data.OleDb.OleDbException E) { connection.Close(); throw new Exception(E.Message); } } } } /// <summary> /// 执行SQL语句，设置命令的执行等待时间 /// </summary> /// <param name="SQLString"></param> /// <param name="Times"></param> /// <returns></returns> public static int ExecuteSqlByTime(string SQLString, int Times) { using (OleDbConnection connection = new OleDbConnection(connectionString)) { using (OleDbCommand cmd = new OleDbCommand(SQLString, connection)) { try { connection.Open(); cmd.CommandTimeout = Times; int rows = cmd.ExecuteNonQuery(); return rows; } catch (System.Data.OleDb.OleDbException E) { connection.Close(); throw new Exception(E.Message); } } } } /// <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) { using (OleDbConnection conn = new OleDbConnection(connectionString)) { conn.Open(); OleDbCommand cmd = new OleDbCommand(); cmd.Connection = conn; OleDbTransaction tx = conn.BeginTransaction(); cmd.Transaction = tx; try { for (int n = 0; n < SQLStringList.Count; n++) { string strsql = SQLStringList[n].ToString(); if (strsql.Trim().Length > 1) { cmd.CommandText = strsql; cmd.ExecuteNonQuery(); } } tx.Commit(); } catch (System.Data.OleDb.OleDbException E) { tx.Rollback(); throw new Exception(E.Message); } } } /// <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) { using (OleDbConnection connection = new OleDbConnection(connectionString)) { OleDbCommand cmd = new OleDbCommand(strSQL, connection); System.Data.OleDb.OleDbParameter myParameter = new System.Data.OleDb.OleDbParameter("@fs", SqlDbType.Image); myParameter.Value = fs; cmd.Parameters.Add(myParameter); try { connection.Open(); int rows = cmd.ExecuteNonQuery(); return rows; } catch (System.Data.OleDb.OleDbException E) { throw new Exception(E.Message); } finally { cmd.Dispose(); connection.Close(); } } } /// <summary> /// 执行一条计算查询结果语句，返回查询结果（object）。 /// </summary> /// <param name="SQLString">计算查询结果语句</param> /// <returns>查询结果（object）</returns> public static object GetSingle(string SQLString) { using (OleDbConnection connection = new OleDbConnection(connectionString)) { using (OleDbCommand cmd = new OleDbCommand(SQLString, connection)) { try { connection.Open(); object obj = cmd.ExecuteScalar(); if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value))) { return null; } else { return obj; } } catch (System.Data.OleDb.OleDbException e) { connection.Close(); throw new Exception(e.Message); } } } } /// <summary> /// 执行查询语句，返回SqlDataReader(使用该方法切记要手工关闭SqlDataReader和连接) /// </summary> /// <param name="strSQL">查询语句</param> /// <returns>SqlDataReader</returns> public static OleDbDataReader ExecuteReader(string strSQL) { OleDbConnection connection = new OleDbConnection(connectionString); OleDbCommand cmd = new OleDbCommand(strSQL, connection); try { connection.Open(); OleDbDataReader myReader = cmd.ExecuteReader(); return myReader; } catch (System.Data.OleDb.OleDbException e) { throw new Exception(e.Message); } //finally //不能在此关闭，否则，返回的对象将无法使用 //{ // cmd.Dispose(); // connection.Close(); //}   } /// <summary> /// 执行查询语句，返回DataSet /// </summary> /// <param name="SQLString">查询语句</param> /// <returns>DataSet</returns> public static DataSet Query(string SQLString) { using (OleDbConnection connection = new OleDbConnection(connectionString)) { DataSet ds = new DataSet(); try { connection.Open(); OleDbDataAdapter command = new OleDbDataAdapter(SQLString, connection); command.Fill(ds, "ds"); } catch (System.Data.OleDb.OleDbException ex) { throw new Exception(ex.Message); } return ds; } } /// <summary> /// 执行查询语句，返回DataSet,设置命令的执行等待时间 /// </summary> /// <param name="SQLString"></param> /// <param name="Times"></param> /// <returns></returns> public static DataSet Query(string SQLString, int Times) { using (OleDbConnection connection = new OleDbConnection(connectionString)) { DataSet ds = new DataSet(); try { connection.Open(); OleDbDataAdapter command = new OleDbDataAdapter(SQLString, connection); command.SelectCommand.CommandTimeout = Times; command.Fill(ds, "ds"); } catch (System.Data.OleDb.OleDbException ex) { throw new Exception(ex.Message); } return ds; } } #endregion #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="SQLString">SQL语句</param> /// <returns>影响的记录数</returns> public static int ExecuteSql(string SQLString, params OleDbParameter[] cmdParms) { using (OleDbConnection connection = new OleDbConnection(connectionString)) { using (OleDbCommand cmd = new OleDbCommand()) { try { PrepareCommand(cmd, connection, null, SQLString, cmdParms); int rows = cmd.ExecuteNonQuery(); cmd.Parameters.Clear(); return rows; } catch (System.Data.OleDb.OleDbException E) { throw new Exception(E.Message); } } } } /// <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OleDbParameter[]）</param> public static void ExecuteSqlTran(Hashtable SQLStringList) { using (OleDbConnection conn = new OleDbConnection(connectionString)) { conn.Open(); using (OleDbTransaction trans = conn.BeginTransaction()) { OleDbCommand cmd = new OleDbCommand(); try { //循环  foreach (DictionaryEntry myDE in SQLStringList) { string cmdText = myDE.Key.ToString(); OleDbParameter[] cmdParms = (OleDbParameter[])myDE.Value; PrepareCommand(cmd, conn, trans, cmdText, cmdParms); int val = cmd.ExecuteNonQuery(); cmd.Parameters.Clear(); trans.Commit(); } } catch { trans.Rollback(); throw; } } } } /// <summary> /// 执行一条计算查询结果语句，返回查询结果（object）。 /// </summary> /// <param name="SQLString">计算查询结果语句</param> /// <returns>查询结果（object）</returns> public static object GetSingle(string SQLString, params OleDbParameter[] cmdParms) { using (OleDbConnection connection = new OleDbConnection(connectionString)) { using (OleDbCommand cmd = new OleDbCommand()) { try { PrepareCommand(cmd, connection, null, SQLString, cmdParms); object obj = cmd.ExecuteScalar(); cmd.Parameters.Clear(); if ((Object.Equals(obj, null)) || (Object.Equals(obj, System.DBNull.Value))) { return null; } else { return obj; } } catch (System.Data.OleDb.OleDbException e) { throw new Exception(e.Message); } } } } /* 何问起 hovertree.com */ /// <summary> /// 执行查询语句，返回SqlDataReader (使用该方法切记要手工关闭SqlDataReader和连接) /// </summary> /// <param name="strSQL">查询语句</param> /// <returns>SqlDataReader</returns> public static OleDbDataReader ExecuteReader(string SQLString, params OleDbParameter[] cmdParms) { OleDbConnection connection = new OleDbConnection(connectionString); OleDbCommand cmd = new OleDbCommand(); try { PrepareCommand(cmd, connection, null, SQLString, cmdParms); OleDbDataReader myReader = cmd.ExecuteReader(); cmd.Parameters.Clear(); return myReader; } catch (System.Data.OleDb.OleDbException e) { throw new Exception(e.Message); } //finally //不能在此关闭，否则，返回的对象将无法使用 //{ // cmd.Dispose(); // connection.Close(); //}   } /// <summary> /// 执行查询语句，返回DataSet /// </summary> /// <param name="SQLString">查询语句</param> /// <returns>DataSet</returns> public static DataSet Query(string SQLString, params OleDbParameter[] cmdParms) { using (OleDbConnection connection = new OleDbConnection(connectionString)) { OleDbCommand cmd = new OleDbCommand(); PrepareCommand(cmd, connection, null, SQLString, cmdParms); using (OleDbDataAdapter da = new OleDbDataAdapter(cmd)) { DataSet ds = new DataSet(); try { da.Fill(ds, "ds"); cmd.Parameters.Clear(); } catch (System.Data.OleDb.OleDbException ex) { throw new Exception(ex.Message); } return ds; } } } private static void PrepareCommand(OleDbCommand cmd, OleDbConnection conn, OleDbTransaction trans, string cmdText, OleDbParameter[] 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 (OleDbParameter parameter in cmdParms) { if ((parameter.Direction == ParameterDirection.InputOutput || parameter.Direction == ParameterDirection.Input) && (parameter.Value == null)) { parameter.Value = DBNull.Value; } cmd.Parameters.Add(parameter); } } } #endregion #region 获取根据指定字段排序并分页查询。 /* 何问起 hovertree.com */ /// <summary> /// 分页查询数据记录总数获取 /// </summary> /// <param name="_tbName">----要显示的表或多个表的连接</param> /// <param name="_ID">----主表的主键</param> /// <param name="_strCondition">----查询条件,不需where</param> /// <param name="_Dist">----是否添加查询字段的 DISTINCT 默认0不添加/1添加</param> /// <returns></returns> public static string getPageListCounts(string _ID, string _tbName, string _strCondition, int _Dist) { //---存放取得查询结果总数的查询语句 //---对含有DISTINCT的查询进行SQL构造 //---对含有DISTINCT的总数查询进行SQL构造  string strTmp = "", SqlSelect = "", SqlCounts = ""; if (_Dist == 0) { SqlSelect = "Select "; SqlCounts = "COUNT(*)"; } else { SqlSelect = "Select DISTINCT "; SqlCounts = "COUNT(DISTINCT " + _ID + ")"; } if (_strCondition == string.Empty) { strTmp = SqlSelect + " "+ SqlCounts + " FROM " + _tbName; } else { strTmp = SqlSelect + " "+ SqlCounts + " FROM " + " Where (1=1) " + _strCondition; } return strTmp; } /// <summary> /// 智能返回SQL语句 /// </summary> /// <param name="primaryKey">主键（不能为空）</param> /// <param name="queryFields">提取字段（不能为空）</param> /// <param name="tableName">表（理论上允许多表）</param> /// <param name="condition">条件（可以空）</param> /// <param name="OrderBy">排序，格式：字段名+""+ASC（可以空）</param> /// <param name="pageSize">分页数（不能为空）</param> /// <param name="pageIndex">当前页，起始为：1（不能为空）</param> /// <returns></returns> public static string getPageListSql(string primaryKey, string queryFields, string tableName, string condition, string orderBy, int pageSize, int pageIndex) { string strTmp = ""; //---strTmp用于返回的SQL语句  string SqlSelect = "", SqlPrimaryKeySelect = "", strOrderBy = "", strWhere = " where 1=1 ", strTop = ""; //0：分页数量 //1:提取字段 //2:表 //3:条件 //4:主键不存在的记录 //5:排序  SqlSelect = " select top {0} {1} from {2} {3} {4} {5}"; //0:主键 //1:TOP数量,为分页数*(排序号-1) //2:表 //3:条件 //4:排序  SqlPrimaryKeySelect = " and {0} not in (select {1} {0} from {2} {3} {4}) "; if (orderBy != "") strOrderBy = " order by " + orderBy; if (condition != "") strWhere += " and " + condition; int pageindexsize = (pageIndex - 1) * pageSize; if (pageindexsize > 0) { strTop = " top " + pageindexsize.ToString(); SqlPrimaryKeySelect = String.Format(SqlPrimaryKeySelect, primaryKey, strTop, tableName, strWhere, strOrderBy); strTmp = String.Format(SqlSelect, pageSize.ToString(), queryFields, tableName, strWhere, SqlPrimaryKeySelect, strOrderBy); } else { strTmp = String.Format(SqlSelect, pageSize.ToString(), queryFields, tableName, strWhere, "", strOrderBy); } return strTmp; } /// <summary> /// 获取根据指定字段排序并分页查询。DataSet /// </summary> /// <param name="pageSize">每页要显示的记录的数目</param> /// <param name="pageIndex">要显示的页的索引</param> /// <param name="tableName">要查询的数据表</param> /// <param name="queryFields">要查询的字段,如果是全部字段请填写：*</param> /// <param name="primaryKey">主键字段，类似排序用到</param> /// <param name="orderBy">是否为升序排列：0为升序，1为降序</param> /// <param name="condition">查询的筛选条件</param> /// <returns>返回排序并分页查询的DataSet</returns> public static DataSet GetPagingList(string primaryKey, string queryFields, string tableName, string condition, string orderBy, int pageSize, int pageIndex) { string sql = getPageListSql(primaryKey, queryFields, tableName, condition, orderBy, pageSize, pageIndex); return Query(sql); } public static string GetPagingListSQL(string primaryKey, string queryFields, string tableName, string condition, string orderBy, int pageSize, int pageIndex) { string sql = getPageListSql(primaryKey, queryFields, tableName, condition, orderBy, pageSize, pageIndex); return sql; } public static int GetRecordCount(string _ID, string _tbName, string _strCondition, int _Dist) { string sql = getPageListCounts( _ID, _tbName, _strCondition, _Dist); object obj = DbHelperACE.GetSingle(sql); if (obj == null) { return 1; } else { return int.Parse(obj.ToString()); } } #endregion  } }