Question

当我尝试运行此代码时，我收到此错误：

conversion failed when converting date and/or time from character string

我在这一行得到错误：

g_muallak_tarihi = DateTime.Parse(row_muallakt["Muallak_tarihi"].ToString());

要存储日期和时间或仅日期的值，我使用DateTime数据类型。我不知道该怎么做。你有什么想法吗？

这是我的代码：

public void cs_hmuallak()
{
    string cs_hmuallak = null;
    SqlConnection cnn;

    cs_hmuallak = @"Data Source= .\SQLEXPRESS; Initial Catalog=mydb;Integrated Security= True";

    cnn = new SqlConnection(cs_hmuallak);

    try
    {
        cnn.Open();

        {
                SqlDataAdapter da_muallakt = new SqlDataAdapter("SELECT M.Muallak_tutari FROM Muallak M INNER JOIN Hasar H ON M.Hasar_no= H.Hasar_no INNER JOIN Police P ON p.Police_no=h.Police_no where p.Acenta_kodu='"+cbx_acenta.Text+"' and p.Brans_kodu='"+cbx_brans.Text+"' and  M.muallak_tarihi<=(Select M.muallak_tarihi from muallak M where M.muallak_tarihi=(select max(muallak_tarihi) from muallak where muallak_tarihi<=@parameter)) and M.Muallak_tarihi=(SELECT max(M.Muallak_tarihi) FROM Muallak M INNER JOIN Hasar H ON M.Hasar_no= H.Hasar_no INNER JOIN Police P ON p.Police_no=h.Police_no where p.Acenta_kodu='"+cbx_acenta.Text+"' and p.Brans_kodu='"+cbx_brans.Text+"' and  M.muallak_tarihi<=(Select M.muallak_tarihi from muallak M where M.muallak_tarihi=(select max(muallak_tarihi) from muallak where muallak_tarihi<=@parameter)) ) ", cnn);

                da_muallakt.SelectCommand.Parameters.AddWithValue("@parameter",g_listetarihi.ToString("yyyy-mm-dd"));
                DataTable table_muallakt = new DataTable();
                da_muallakt.Fill(table_muallakt);
                foreach (DataRow row_muallakt in table_muallakt.Rows)
                {
                    if (row_muallakt["Muallak_tutari"] != DBNull.Value)
                    {
                        if (row_muallakt["Muallak_tarihi"] != DBNull.Value)
                        {
                            g_muallak_tarihi = DateTime.Parse(row_muallakt["Muallak_tarihi"].ToString());
                            g_muallak_tutari = int.Parse(row_muallakt["Muallak_tutari"].ToString());
                        }
                    }
                }                   
        }
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.ToString());
    }
}

Answer 1

假设Muallak_tarihi被定义为DATETIME列（应该就像它所持有的那样），所有这些与转换为字符串和从字符串转换的工作都是不需要。

您可以直接使用GetDateTime数据阅读器来获取它，或者只是转换值：

g_muallak_tarihi = row_muallakt["Muallak_tarihi"] as DateTime;

此外，您使用的参数（@parameter）也应该是DATETIME - 并且只是直接传入，而不是使用ToString：< / p>

da_muallakt.SelectCommand.Parameters.AddWithValue("@parameter",g_listetarihi);

Answer 2

使用string.Format

da_muallakt.SelectCommand.Parameters.AddWithValue("@parameter", string.Format("{0:yyyy-MM-dd}",g_listetarihi.ToString());

MSDN DateTime格式：http://msdn.microsoft.com/en-us/library/8kb3ddd4.aspx

从字符串转换日期和/或时间时出错

2 个答案: