/// 
 /// 执行SQL语句没有返回结果,如:执行删除、更新、插入等操作
 /// 
 /// 
 /// 操作成功标志
 public bool ExeSQL(string strSQL)
 {
 bool resultState = false;
 Connection.Open();
 OleDbTransaction myTrans = Connection.BeginTransaction();
 OleDbCommand command = new OleDbCommand(strSQL, Connection, myTrans);
 try
 {
 command.ExecuteNonQuery();
 myTrans.Commit();
 resultState = true;
 }
 catch
 {
 myTrans.Rollback();
 resultState = false;
 }
 finally
 {
 Connection.Close();
 }
 return resultState;
 }
 /// 
 /// 执行SQL语句返回结果到DataReader中
 /// 
 /// 
 /// dataReader
 private OleDbDataReader ReturnDataReader(string strSQL)
 {
 Connection.Open();
 OleDbCommand command = new OleDbCommand(strSQL, Connection);
 OleDbDataReader dataReader = command.ExecuteReader();
 Connection.Close();
 return dataReader;
 }
 /// 
 /// 执行SQL语句返回结果到DataSet中
 /// 
 /// 
 /// DataSet
 public DataSet ReturnDataSet(string strSQL)
 {
 Connection.Open();
 DataSet dataSet = new DataSet();
 OleDbDataAdapter OleDbDA = new OleDbDataAdapter(strSQL, Connection);
 OleDbDA.Fill(dataSet, "objDataSet");
 Connection.Close();
 return dataSet;
 }
 /// 
 /// 执行一查询语句,同时返回查询结果数目
 /// 
 /// 
 /// sqlResultCount
 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;
 }
 }//
}//
 好了,数据库访问、数据库操作的公用类完成了,详细代码意义大家自己看吧,这些属于C# 语法知识了,现在可以编译生成项目了,编译完后把项目的dll文件Com.LXJ.dll拷贝到Example项目下的bin目录中,然后在项目Example中引入Com.LXJ.dll即可。稍后介绍如何使用它,休息一下,喝口水,呵呵.....