写法一:        public static DataTable GetTable(string safeSqlString)    {        OleDbCommand cmd = new OleDbCommand(safeSqlString, GetConnection());        OleDbDataAdapter da = new OleDbDataAdapter(cmd);        DataTable dt = new DataTable();        da.Fill(dt);        return dt;    }    public static DataRow GetRow(string safeSqlString)    {        DataRow dr = null;        DataTable dt = GetTable(safeSqlString);        if (dt.Rows.Count > 0)        {            dr = dt.Rows[0];        }        return dr;    } 写法二:    public static DataTable GetTable(string safeSqlString)    {        OleDbCommand cmd = new OleDbCommand(safeSqlString, GetConnection());        OleDbDataAdapter da = new OleDbDataAdapter(cmd);        DataTable dt = new DataTable();        da.Fill(dt);        return dt;    }    public static DataRow GetRow(string safeSqlString)    {        OleDbCommand cmd = new OleDbCommand(safeSqlString, GetConnection());        OleDbDataAdapter da = new OleDbDataAdapter(cmd);        DataTable dt = new DataTable();        da.Fill(dt);        DataRow dr = null;        if (dt.Rows.Count > 0)        {            dr = dt.Rows[0];        }        return dr;    }针对GetRow(),哪种写法好些 ,效率优先