直接代码吧：

///

/// Oracle数据库连接

///

/// 数据库连接串，例如：(DESCRIPTION =(ADDRESS_LIST =(ADDRESS = (PROTOCOL = TCP)(HOST = IP)(PORT = *)))(CONNECT_DATA =(SERVICE_NAME = *)))

/// 用户名

/// 用户密码

/// Oracle数据库连接对象

private static OracleConnection ConnectOracle(string path, string user, string psw)

{

OracleConnection oracleConn = new OracleConnection();

string connectionStr = string.Format("Data Source={0};User Id={1};Password={2};", path, user, psw);

oracleConn.ConnectionString = connectionStr;

return oracleConn;

}

///

/// Access数据库连接

///

/// 数据库连接串，例如：@"D:\qingdan.accdb;"

/// Access版本，true为高于2007版

/// Access数据库连接对象

private static OleDbConnection ConnectOracle(string path,bool flag)

{

OleDbConnection accessConn = null;

if (string.IsNullOrWhiteSpace(path) || !File.Exists(path))

{

MessageBox.Show("Acess数据库文件不存在", "错误提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);

return accessConn;

}

string conStr = null;

if (flag)

{

conStr = "Provider=Microsoft.Ace.OleDb.12.0;";

conStr += "Data Source=" + path;

conStr += ";Persist Security Info=False;";

}

else

{

conStr = "Provider=Microsoft.Jet.OLEDB.4.0;";

conStr += "Data Source=" + path;

}

accessConn = new OleDbConnection(conStr);

return accessConn;

}

以上是建立数据库连接的方法。

对Oracle数据库的查询操作方法如下：

string sqlTest = "";//此处为查询SQL

m_dsSet = new DataSet();//查询结果集合

OracleDataAdapter command = new OracleDataAdapter(sqlTest, m_oracleConn);

command.Fill(m_dsSet, "ds");

对Access数据库操作：

OleDbCommand dbCommand = new OleDbCommand();

dbCommand.Connection = m_accessConn;//连接串

dbCommand.Transaction = m_accessConn.BeginTransaction();

dbCommand.CommandText ="";//操作命令SQL

dbCommand.ExecuteNonQuery();

dbCommand.Transaction.Commit();