数据库类(Access专用) 未测试

using System;
using System.Data;
using System.Configuration;
using System.Data.OleDb;


/// <summary>
/// 通用数据库类(Access专用)未测试
/// <author>ZhengFei</author>
/// <version>2.0版</version>
/// <realseDate>2007-5-10</realseDate>
/// </summary>
namespace AccessDataBase
{
    public class AccDataBase
    {
        string _ConnStr = "";
        /// <summary>
        /// 不带参数的构造函数（默认取web.config中的连接字符串）
        /// </summary>
        public AccDataBase()
        {
            _ConnStr = ConfigurationManager.ConnectionStrings["AccConn"].ToString();
        }
        /// <summary>
        /// 构造函数（重载，带连接字符串）
        /// </summary>
        /// <param name="connstr">数据库连接字符串</param>
        public AccDataBase(string connstr)
        {
            try
            {
                this._ConnStr = connstr;
            }
            catch (Exception ep)
            {
                throw ep;
            }
        }
        /// <summary>
        /// 数据库链接字符串
        /// </summary>
        public string ConnStr
        {
            get
            {
                return _ConnStr;
            }
            set
            {
                _ConnStr = value;
            }
        }
        /// <summary>
        /// 获得一个已连接数据库的OleDbConnection对象
        /// </summary>
        /// <returns>返回一个已连接数据库的OleDbConnection对象</returns>
        public OleDbConnection GetConn()
        {
            OleDbConnection Conn = new OleDbConnection(_ConnStr);
            try
            {
                Conn.Open();
            }
            catch
            {
                throw;
            }
            return Conn;
        }
        /// <summary>
        /// 释放资源，并回收垃圾
        /// </summary>
        /// <returns></returns>
        public void Dispose(OleDbConnection Conn)
        {
            if (Conn != null)
            {
                Conn.Close();
                Conn.Dispose();
            }
            GC.Collect();
        }
        /// <summary>
        /// 生成Command对象
        /// </summary>
        /// <param name="SQL">SQL语句</param>
        /// <param name="Conn">OledbConnection对象</param>
        /// <returns></returns>
        public OleDbCommand CreateCommand(string SQL, OleDbConnection Conn)
        {
            if (Conn.State != ConnectionState.Open)
            {
                try
                {
                    Conn.Open();

                }
                catch
                {
                    throw;
                }
            }
            OleDbCommand Cmd = new OleDbCommand(SQL, Conn);
            return Cmd;
        }

        /// <summary>
        /// 返回adapter对象
        /// </summary>
        /// <param name="SQL">SQL语句</param>
        /// <param name="Conn">SqlConnection连接对象</param>
        /// <returns>返回adapter对象</returns>
        public OleDbDataAdapter CreateDataAdapter(string SQL, OleDbConnection Conn)
        {
            if (Conn.State != ConnectionState.Open)
            {
                try
                {
                    Conn.Open();
                }
                catch
                {
                    throw;
                }
            }
            OleDbDataAdapter Da = new OleDbDataAdapter(SQL, Conn);
            return Da;
        }
        public OleDbDataAdapter CreateDataAdapter(OleDbCommand cmd)
        {
            OleDbDataAdapter Da = new OleDbDataAdapter(cmd);
            return Da;
        }
        /// <summary>
        /// 验证是否有数据
        /// </summary>
        /// <param name="SQL">SQL语句</param>
        /// <returns></returns>
        public bool ExistDate(string SQL)
        {
            OleDbConnection Conn = this.GetConn();
            OleDbDataReader dr;
            dr = this.CreateCommand(SQL, Conn).ExecuteReader();
            if (dr.Read())
            {
                Dispose(Conn);
                return true;
            }
            else
            {
                Dispose(Conn);
                return false;
            }
        }
        /// <summary>
        /// 返回一个带参数的OledbCommand对象
        /// </summary>
        /// <param name="SQL">SQL语句</param>
        /// <param name="Conn">OLEDBConnection对象</param>
        /// <param name="sp">OleDbParameter数组</param>
        /// <returns></returns>
        public OleDbCommand CreateCommand(string SQL, OleDbConnection Conn, OleDbParameter[] sp)
        {
            try
            {
                if (Conn.State != ConnectionState.Open)
                {
                    Conn.Open();
                }
            }
            catch
            {
                throw;
            }
            OleDbCommand Cmd = new OleDbCommand(SQL, Conn);
            if (sp != null)
            {
                Cmd.Parameters.Clear();
                foreach (OleDbParameter s in sp)
                    Cmd.Parameters.Add(s);
            }
            return Cmd;
        }
        /// <summary>
        /// 执行无参数的OLEDBCommand对象（无返回）
        /// </summary>
        /// <param name="SQL">SQL语句</param>
        public void Execute(string SQL)
        {
            OleDbConnection conn = new OleDbConnection(ConnStr);
            conn.Open();
            try
            {
                CreateCommand(SQL, conn).ExecuteNonQuery();
            }
            catch
            {
                throw;
            }
            finally
            {
                Dispose(conn);
            }
            return;
        }
        /// <summary>
        /// 执行有参数的OLEDBCommand对象（无返回）
        /// </summary>
        /// <param name="SQL">SQL语句</param>
        /// <param name="SP">OleDbParameter参数数组</param>
        public void Execute(string SQL, OleDbParameter[] SP)
        {
            OleDbConnection conn = new OleDbConnection(ConnStr);
            conn.Open();
            try
            {
                CreateCommand(SQL, conn, SP).ExecuteNonQuery();
            }
            catch
            {
                throw;
            }
            finally
            {
                Dispose(conn);
            }
            return;
        }
        /// <summary>
        /// 执行SQL语句返回OledbDataReader（记得关闭）
        /// </summary>
        /// <param name="SQL"></param>
        /// <returns></returns>
        public OleDbDataReader ExecuteReader(string SQL)
        {
            OleDbDataReader dr;
            OleDbConnection conn = new OleDbConnection(ConnStr);
            conn.Open();
            try
            {
                dr = CreateCommand(SQL, conn).ExecuteReader();
            }
            catch
            {
                throw;
            }
            return dr;
        }
        /// <summary>
        /// 执行SQL语句返回OledbDataReader（记得关闭）
        /// </summary>
        /// <param name="SQL">SQL语句</param>
        /// <param name="SP">OleDbParameter数组</param>
        /// <returns></returns>
        public OleDbDataReader ExecuteReader(string SQL, OleDbParameter[] SP)
        {
            OleDbDataReader dr;
            OleDbConnection conn = new OleDbConnection(ConnStr);
            conn.Open();
            try
            {
                dr = CreateCommand(SQL, conn, SP).ExecuteReader();
            }
            catch
            {
                throw;
            }
            return dr;
        }
        /// <summary>
        /// 执行SQL语句返回DataSet
        /// </summary>
        /// <param name="SQL"></param>
        /// <returns></returns>
        public DataSet ExecuteDataSet(string SQL, string TableName)
        {
            DataSet ds = new DataSet();
            OleDbConnection conn = new OleDbConnection(ConnStr);
            conn.Open();
            try
            {
                CreateDataAdapter(SQL, conn).Fill(ds, TableName);
            }
            catch
            {
                throw;
            }
            finally
            {
                Dispose(conn);
            }

            return ds;
        }
        /// <summary>
        /// 执行SQL语句返回DataSet
        /// </summary>
        /// <param name="SQL">SQL语句</param>
        /// <param name="TableName">表名</param>
        /// <param name="sp">参数数组</param>
        /// <returns></returns>
        public DataSet ExecuteDataSet(string SQL, string TableName, OleDbParameter[] sp)
        {
            DataSet ds = new DataSet();
            OleDbConnection conn = new OleDbConnection(ConnStr);
            conn.Open();
            try
            {
                CreateDataAdapter(CreateCommand(SQL, conn, sp)).Fill(ds, TableName);
            }
            catch
            {
                throw;
            }
            finally
            {
                Dispose(conn);
            }
            return ds;
        }
        /// <summary>
        /// 创建输入参数
        /// </summary>
        /// <param name="ParameterName">参数名称</param>
        /// <param name="DbType">参数类型</param>
        /// <param name="Size">参数大小</param>
        /// <param name="Value">参数值</param>
        /// <returns>新的参数</returns>
        public OleDbParameter MakeInputParameter(string ParameterName, OleDbType DbType, int Size, object Value)
        {
            return MakeParameter(ParameterName, DbType, Size, ParameterDirection.Input, Value);
        }

        /// <summary>
        /// 创建输出参数
        /// </summary>
        /// <param name="ParameterName">参数名称</param>
        /// <param name="DbType">参数类型</param>
        /// <param name="Size">参数大小</param>
        /// <returns>新的参数</returns>
        public OleDbParameter MakeOutParameter(string ParameterName, OleDbType DbType, int Size)
        {
            return MakeParameter(ParameterName, DbType, Size, ParameterDirection.Output, null);
        }

        /// <summary>
        /// 创建储存过程参数
        /// </summary>
        /// <param name="ParameterName">参数名称</param>
        /// <param name="DbType">参数类型</param>
        /// <param name="Size">参数大小</param>
        /// <param name="Direction">参数方法</param>
        /// <param name="Value">参数值</param>
        /// <returns>新的参数</returns>
        public OleDbParameter MakeParameter(string ParameterName, OleDbType DbType, Int32 Size, ParameterDirection Direction, object Value)
        {
            OleDbParameter AccParam;
            if (Size > 0)
            {
                AccParam = new OleDbParameter(ParameterName, DbType, Size);
            }
            else
            {
                AccParam = new OleDbParameter(ParameterName, DbType);
            }

            AccParam.Direction = Direction;
            if (!(Direction == ParameterDirection.Output && Value == null))
            {
                AccParam.Value = Value;
            }
            return AccParam;
        }
        /// <summary>
        /// 查询指定数量数据，返回DataSet（用于分页）
        /// </summary>
        /// <param name="TableName">表名</param>
        /// <param name="PK">主键</param>
        /// <param name="Fields">要查询的字段</param>
        /// <param name="Sort">排序字段</param>
        /// <param name="Filter">查询条件</param>
        /// <param name="PageSize">每页大小</param>
        /// <param name="CurrentPage">当前页码</param>
        /// <returns></returns>
        public DataSet GetDataSet(string TableName, string PK, string Fields, string Sort, string Filter, int PageSize, int CurrentPage)
        {
            DataSet ds = new DataSet();
            OleDbConnection conn=new OleDbConnection(ConnStr);
            conn.Open();
            string sql = "", and = "";
            int num = 0;
            if (Fields == "") Fields = "*";
            if (Sort == "")
            {
                Sort = string.Format("order by {0} asc", PK);
            }
            else
            {
                Sort = string.Format("order by {0}", Sort);
            }
            if (PageSize <= 0) PageSize = 10;
            if (CurrentPage < 1) CurrentPage = 1;
            num = (CurrentPage - 1) * PageSize;
            if (Filter != "")
            {
                Filter = "where (" + Filter + ")";
                and = "and";
            }
            else
            {
                and = "where";
            }
            if (CurrentPage == 1)
            {
                sql = string.Format("select top {0} {1} from {2} {3} {4}", PageSize, Fields, TableName, Filter, Sort);
            }
            else
            {
                sql = string.Format("select top {0} {1} from {2} {3} {4} ({5} not in(select top {6} {7} from {8} {9} {10})) {11}", PageSize, Fields, TableName, Filter, and, PK, num, PK, TableName, Filter, Sort, Sort);
            }
            ds = ExecuteDataSet(sql, TableName);
            return ds;
        }
        /// <summary>
        /// 查询指定数量数据，返回OleDbDataReader（用于分页）
        /// </summary>
        /// <param name="TableName">表名</param>
        /// <param name="PK">主键</param>
        /// <param name="Fields">要查询的字段</param>
        /// <param name="Sort">排序字段</param>
        /// <param name="Filter">查询条件</param>
        /// <param name="PageSize">每页大小</param>
        /// <param name="CurrentPage">当前页码</param>
        /// <returns></returns>
        public OleDbDataReader GetDataReader(string TableName, string PK, string Fields, string Sort, string Filter, int PageSize, int CurrentPage)
        {
            OleDbDataReader dr;
            OleDbConnection conn = new OleDbConnection(ConnStr);
            conn.Open();
            string sql = "", and = "";
            int num = 0;
            if (Fields == "") Fields = "*";
            if (Sort == "")
            {
                Sort = string.Format("order by {0} asc", PK);
            }
            else
            {
                Sort = string.Format("order by {0}", Sort);
            }
            if (PageSize <= 0) PageSize = 10;
            if (CurrentPage < 1) CurrentPage = 1;
            num = (CurrentPage - 1) * PageSize;
            if (Filter != "")
            {
                Filter = "where (" + Filter + ")";
                and = "and";
            }
            else
            {
                and = "where";
            }
            if (CurrentPage == 1)
            {
                sql = string.Format("select top {0} {1} from {2} {3} {4}", PageSize, Fields, TableName, Filter, Sort);
            }
            else
            {
                sql = string.Format("select top {0} {1} from {2} {3} {4} ({5} not in(select top {6} {7} from {8} {9} {10})) {11}", PageSize, Fields, TableName, Filter, and, PK, num, PK, TableName, Filter, Sort, Sort);
            }
            dr = ExecuteReader(sql);
            return dr;
        }
    }
}