C#实现的ACCESS数据库操作类完整实例

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,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,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,cmdParms);
            object obj = cmd.ExecuteScalar();
            cmd.Parameters.Clear();
            if ((Object.Equals(obj,System.DBNull.Value)))
            {
              return null;
            }
            else
            {
              return obj;
            }
          }
          catch (System.Data.OleDb.OleDbException e)
          {
            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 SQLString,params OleDbParameter[] cmdParms)
    {
      OleDbConnection connection = new OleDbConnection(connectionString);
      OleDbCommand cmd = new OleDbCommand();
      try
      {
        PrepareCommand(cmd,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,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。
    
    /// <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,SqlPrimaryKeySelect,strOrderBy);
      }
      else
      {
        strTmp = String.Format(SqlSelect,"",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,int pageIndex)
    {
      string sql = getPageListSql(primaryKey,condition,orderBy,pageSize,pageIndex);
      return Query(sql);
    }
    public static string GetPagingListSQL(string primaryKey,pageIndex);
      return sql;
    }
    public static int GetRecordCount(string _ID,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
  }
}