Question

我正在创建一个项目，用户必须在Combobox中选择日期，但是在Combobox中选择显示错误日期的日期

字符串未被识别为有效的DateTime。” 我正在尝试从slq中的数据库中获取日期。以下是我的代码

            System.Data.DataTable dt;
       SqlConnection con=new SqlConnection(@"Data Source=krupal;Initial Catalog=LOANNOTICE;Integrated Security=True");
        con.Open();
        this.cmbmonth.FormatString = "yyyy/ MM/dd";
        // DateTime dat = Convert.ToDateTime(cmbmonth.SelectedItem.ToString("yyyy/MM/dd"));
        //var date = cmbmonth.Text;
       //var d1 = Convert.ToDateTime(cmbmonth.Text);
       // MessageBox.Show("" + d1);
        string Querie=("SELECT HCODE ,(select top 1  rtrim(Name) From RNSB_TEST.dbo.FC014076 p with(nolock) where  convert(varchar,PrdCd) = convert(varchar,HCODE)) as PrdName,count(*) as NoOfAcc,round(Sum(BAL2802),2) as PrintAmt ,round(SUM(IntAmt),2) as TotalInt,0 as TDSAmount, round(SUM(IntAmt),2) as NetIntAmt, round((Sum(BAL2802) + SUM(IntAmt)),2)as TotalAmt from LOANNOTICE.dbo.UNCLAIM_DEPO with(nolock) where EffeDate='"+Convert.ToDateTime(cmbmonth.SelectedText).ToString("yyyy/MM/dd") + "' group by HCODE union SELECT HCODE, (select top 1  rtrim(Name) From RNSB_TEST.dbo.FC014076 p with(nolock) where  convert(varchar, PrdCd) = convert(varchar, HCODE)) as PrdName,count(*) as NoOfAcc,round(Sum(MatAmt), 2) as PrintAmt ,round(SUM(IntAmt), 2) as TotalInt,round(sum(TDS_Amount), 2) as TDSAmount, round(SUM(Net_Int), 2) as NetIntAmt, round((Sum(MatAmt) + SUM(Net_Int)), 2) as TotalAmt from LOANNOTICE.dbo.UNCLAIM_DEPO_TDR with(nolock) where EffeDate = '"+Convert.ToDateTime(cmbmonth.SelectedText).ToString("yyyy/MM/dd") + "' group by HCODE");
        SqlCommand cmd = new SqlCommand(Querie, con);
        SqlDataAdapter sda = new SqlDataAdapter(cmd);
        dt = new System.Data.DataTable();
        sda.Fill(dt);

任何人都有解决方案，请尽快告诉我。谢谢。

Answer 1

您需要将字符串解析为有效的日期时间。

您的转换错误，请将字符串转换为日期时间，然后传递到适当的日期字段。

请参阅此link。

Answer 2

我引起您的注意，这里您有空白处

this.cmbmonth.FormatString = "yyyy/ MM/dd"

无论如何，您应该始终检查以字符串形式传递的日期，如果无法转换则抛出异常：

if (!DateTime.TryParse(_date, out DateTime date))
{
    throw new InvalidCastException("Not a valid date.");
}

最后，尝试以这种方式设置SqlCommand参数，使其更具可读性，并且您不必处理字符串插值（签出用于：

using (DbConnection connection = new SqlConnection("MyConnectionString"))
{
    using (DbCommand command = new SqlCommand(connection))
    {
        command.CommandType = System.Data.CommandType.Text;
        command.CommandText = "SELECT * FROM MyTable WHERE Date = @Date";
        command.Parameters.Add("@Date", SqlDbType.Date);
        command.Parameters["@Date"].Value = date;
    }
}

试试看！：）

致谢！

日期不与组合选择项目的数据库比较

2 个答案: