Question

我正在尝试使用.net读取数据库的所有记录，而我在while循环中有一个逻辑错误，我无法理解问题是什么，如果有人可以看看我会非常感激

{
    System.Data.OleDb.OleDbConnection  con;
    DataSet dsl;
    System.Data.OleDb.OleDbDataAdapter da;
    public String accessDatabase()
    {
        initializecomponent();

        con = new System.Data.OleDb.OleDbConnection();
        con.ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\\Users\\Owner\\Documents\\CIS3052.mdb";
        dsl = new DataSet();
        String displayID = null;
         String displayFname = null;
         String displayLname = null;
         String displayAge = null;
         String displayJob = null;
         String viewAll = null;
         int inc = 0;
         int MaxRows = 0;


        string sql = "SELECT * FROM Employee";
        da = new System.Data.OleDb.OleDbDataAdapter(sql, con);
        con.Open();
        da.Fill(dsl, "Employee");

        MaxRows = dsl.Tables["Employee"].Rows.Count;
        while (inc != MaxRows -1)
        {

        DataRow dRow = dsl.Tables["Employee"].Rows[inc];
        displayID = dRow.ItemArray.GetValue(0).ToString();
        displayFname = dRow.ItemArray.GetValue(1).ToString();
        displayLname = dRow.ItemArray.GetValue(2).ToString();
        displayAge = dRow.ItemArray.GetValue(3).ToString();
        displayJob = dRow.ItemArray.GetValue(4).ToString();
        viewAll = viewAll + displayID + " " + displayFname + " " + displayLname + " " + displayAge + " " + displayJob + " ";
        }



        con.Close();
        con.Dispose();



        return viewAll;
    }


}

}

Answer 1

为什么不尝试使用For-Loop ??

for(int i = 0; i < MaxRows; i++)
{    
    DataRow dRow = dsl.Tables["Employee"].Rows[i];
    displayID = dRow.ItemArray.GetValue(0).ToString();
    displayFname = dRow.ItemArray.GetValue(1).ToString();
    displayLname = dRow.ItemArray.GetValue(2).ToString();
    displayAge = dRow.ItemArray.GetValue(3).ToString();
    displayJob = dRow.ItemArray.GetValue(4).ToString();
    viewAll = viewAll + displayID + " " + displayFname + " " + displayLname + " " + displayAge + " " + displayJob + " ";
}

Answer 2

替换 while（inc！= MaxRows -1） {

与 for（int inc = 0; inc＆lt; MaxRows; inc ++） {

尝试保存数据库记录时循环中的逻辑错误

2 个答案: