链接数据库的问题 进来帮个帮吗！！！

Question

/// 数据库连接字符串
/// </summary>
private string m_sConnectionString;

//数据库连接对象
private SqlConnection m_sqlConnection;
private SqlCommand m_sqlCommand;
private SqlTransaction m_sqlTransaction;
private SqlDataAdapter m_sqlDataAdapter ;

/// <summary>
/// 构造函数，初始化内部变量
/// </summary>
public DataBaseOperate(): this(  "uid=sa;pwd=;server=.;database=Student")
{                          /\
                            |
                            |
                            |------------这样写是什么意思啊？
                            |             
}                           |
                            |
                            |
/// <summary>               |
/// 构造函数                |
/// </summary>              \/public DataBaseOperate(string sConnectionString)
{
if (sConnectionString != "")
{
m_sConnectionString = sConnectionString;

}

}