c# - 错误的日期格式 C#、Oracle

Question

我正在尝试以正确的格式 (dd/mm/yyyy) 获取我的日期。目前它的格式是:MM-DD-YYYY HH24:MI:SS 当我将它更改为 dd/mm/yyyy 时，它在数据库 (Oracle) 中工作。一旦我在我的应用程序中运行它，我就会得到异常:IndexOutOfRange at :

this.InfoList9.Add(dr["start_rcv_datetime"].ToString());

请看下面我的代码。

public List<String> InfoList = new List<String>();

private void populatelblDate()
{
    conn.Open();
    string query;
    query = "select to_char(dg.start_rcv_datetime,'dd/mm/yyyy') from dc_pallet dp, dc_pallet_stock dps , dc_grv dg , sku s ,prod_size ps,colour c ,purch_order_carton_sku pocs , dc_crane_instruc dci where dps.pallet_id_no = '" + palletId.ToString() + "' and dp.pallet_id_no = dps.pallet_id_no and dg.dc_grv_id_no = dps.dc_grv_id_no and dg.order_no = dps.order_no and dg.company_id_no = dps.company_id_no and s.company_id_no = dps.company_id_no and s.company_id_no = dg.company_id_no and dps.company_id_no = c.company_id_no and dps.company_id_no = ps.company_id_no and s.prod_size_id_no = ps.prod_size_id_no and s.colour_id_no = c.colour_id_no and dps.company_id_no = ps.company_id_no and pocs.order_no = dps.order_no and pocs.carton_code = dps.carton_code and pocs.company_id_no = dps.company_id_no and pocs.sku_id_no = s.sku_id_no and dci.pallet_id_no(+) = dp.pallet_id_no";

    OracleCommand cmd = new OracleCommand(query, conn);
    OracleDataReader dr = cmd.ExecuteReader();
    while (dr.Read())
    {
        this.InfoList.Add(dr["start_rcv_datetime"].ToString());
    }
    dr.Close();
    conn.Close();
}

private void frmInfo_Load(object sender, EventArgs e)
{ 
    populatelblDate();
    lbl1.Text = this.InfoList[0];
}

然后我还有一个上一个和下一个按钮...

Answer 1

您的 IndexOutOfRange 异常表明直接问题是结果集不包含 start_rcv_datetime 列 - 大概是因为to_char 转换。

根本不要在数据库端处理字符串。获取作为 DateTime 的值，然后在客户端 将其格式化为任何您想要的格式。

使用 dr.GetDateTime 获取值，从查询中删除 to_char 部分:

query = "select dg.start_rcv_datetime from ...";

using (OracleCommand cmd = new OracleCommand(query, conn))
{
    using (OracleDataReader dr = cmd.ExecuteReader())
    {
        int dateColumn = dr.GetOrdinal("start_rcv_datetime");
        while (dr.Read())
        {
            DateTime date = dr.GetDateTime(0);
            // Or whatever - consider cultural implications
            string text = date.ToString("dd/MM/yyyy");
            InfoList.Add(text);
        }
    }
}

(注意 using 语句 - 您应该始终确保清理与数据库相关的资源。)