C#訪問Access數據類

配置web.config文件的鏈接參數

<configuration>

  <appSettings>
    <add key="connStr" value="/App_Data/abc.mdb" />
  </appSettings>
    <connectionStrings/>

C#代碼

 

using System;
using System.Data;
using System.Data.SqlClient;
using System.Data.OleDb;

namespace Conn
...{
    public class ConnDB
    ...{
        /**//// <summary>
        /// 連接數據庫字符串
        /// </summary>
        private string connectionString;

        /**//// <summary>
        /// 存儲數據庫連接（保護類，只有由它派生的類才能訪問）
        /// </summary>
        protected OleDbConnection Connection;

        /**//// <summary>
        /// 構造函數：數據庫的默認連接
        /// </summary>
        public ConnDB()
        ...{
            string connStr;
            connStr = System.Configuration.ConfigurationSettings.AppSettings["connStr"]; //從web.config配置中讀取

            connectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Common.applicationPath + connStr;

            Connection = new OleDbConnection(connectionString);
        }

        /**//// <summary>
        /// 構造函數：帶有參數的數據庫連接
        /// </summary>
        /// <param name="newConnectionString">連接語句</param>
        public ConnDB(string newConnectionString)
        ...{
            connectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Common.applicationPath + newConnectionString;
            Connection = new OleDbConnection(connectionString);
        }

        /**//// <summary>
        /// 獲得連接字符串
        /// </summary>
        public string ConnectionString
        ...{
            get ...{ return connectionString; }
        }


        /**//// <summary>
        /// 執行SQL語句沒有返回結果，如：執行刪除、更新、插入等操作
        /// </summary>
        /// <param name="strSQL">SQL語句</param>
        /// <returns>是否成功</returns>
        public bool ExeSQL(string strSQL)
        ...{
            bool resultState = false;
            OleDbTransaction myTrans = null;
            OleDbCommand command = null;

            try
            ...{
                Connection.Open();
                myTrans = Connection.BeginTransaction();
                command = new OleDbCommand(strSQL, Connection, myTrans);
                command.ExecuteNonQuery();
                myTrans.Commit();
                resultState = true;
            }
            catch
            ...{
                if (myTrans != null)
                    myTrans.Rollback();
                resultState = false;
            }
            finally
            ...{
                Connection.Close();
            }
            return resultState;
        }

        /**//// <summary>
        /// 執行SQL語句返回結果到DataReader中
        /// </summary>
        /// <param name="strSQL">SQL語句</param>
        /// <returns>DataReader</returns>
        public OleDbDataReader ReturnDataReader(string strSQL)
        ...{
            OleDbDataReader dataReader = null;
            try
            ...{
                Connection.Open();
                OleDbCommand command = new OleDbCommand(strSQL, Connection);
                dataReader = command.ExecuteReader();
            }
            catch
            ...{
                Connection.Close();
            }
            return dataReader;
        }

        /**//// <summary>
        /// 執行SQL語句返回結果到DataSet中
        /// </summary>
        /// <param name="strSQL">SQL語句</param>
        /// <returns>DataSet</returns>
        public DataSet ReturnDataSet(string strSQL)
        ...{
            DataSet dataSet = null;
            try
            ...{
                Connection.Open();
                dataSet = new DataSet();
                OleDbDataAdapter OleDbDA = new OleDbDataAdapter(strSQL, Connection);
                OleDbDA.Fill(dataSet, "objDataSet");
            }
            finally
            ...{
                Connection.Close();
            }
            return dataSet;
        }

        /**//// <summary>
        /// 執行一查詢語句，同時返回查詢結果數目
        /// </summary>
        /// <param name="strSQL">SQL語句</param>
        /// <returns>結果數</returns>
        public int ReturnSqlResultCount(string strSQL)
        ...{
            int sqlResultCount = 0;

            try
            ...{
                Connection.Open();
                OleDbCommand command = new OleDbCommand(strSQL, Connection);
                OleDbDataReader dataReader = command.ExecuteReader();

                while (dataReader.Read())
                ...{
                    sqlResultCount++;
                }
                dataReader.Close();
            }
            catch
            ...{
                sqlResultCount = 0;
            }
            finally
            ...{
                Connection.Close();
            }
            return sqlResultCount;
        }

        /**//// <summary>
        /// 關閉連接
        /// </summary>
        public void close()
        ...{
            if (Connection != null)
                Connection.Close();
        }
    }
}