Question

    SqlConnection con = new SqlConnection("Data Source=RANJEETMAURYA;Initial    Catalog=Project;Integrated Security=True");
    con.Open();

    DateTime current = DateTime.Now;

    //DateTime CurrentDate;
    //CurrentDate = Convert.ToDateTime(DateTime.Now.ToString("dd-MMM-yyyy"));
    current = Convert.ToDateTime(DateTime.Now.ToString("MM/dd/yyyy hh:mm"));

    SqlCommand cmd = new SqlCommand(@"INSERT INTO CustomerDetails
                      (Date, Name, Gender, Address, Contact_No, Email_ID)
VALUES        ('" +current+ "','" + txtName.Text + "','" + Gender + "','" +     txtAddress.Text + "','" + txtContact.Text + "','" + txtEmail.Text + "')", con);
    cmd.ExecuteNonQuery();
    con.Close();
    MessageBox.Show("Customer Information Added Successfully.", "Dairy  Management System", MessageBoxButtons.OK, MessageBoxIcon.Information);
    SQLFunctions.Refresh(this.dataGridCustomerDetails);

这是错误请帮帮我出于什么原因它运行了几次，它没有运行一段时间。

 System.FormatException was unhandled
  HResult=-2146233033
Message=String was not recognized as a valid DateTime.
Source=mscorlib
StackTrace:
   at System.DateTimeParse.Parse(String s, DateTimeFormatInfo dtfi, DateTimeStyles  styles)
   at System.Convert.ToDateTime(String value)
   at IndianDiary.frmCustomerDetails.btnAddNew_Click(Object sender, EventArgs e) in

Answer 1

您正在将当前时间转换为字符串，然后将字符串解析回DateTime：

DateTime current = DateTime.Now;
current = Convert.ToDateTime(DateTime.Now.ToString("MM/dd/yyyy hh:mm"));

这有什么意义？只需使用DateTime.Now即可。还可以使用命令参数。

string sql = @"INSERT INTO CustomerDetails
               (Date, Name, Gender, Address, Contact_No, Email_ID)
               VALUES (@date, @name, @gender, @address, @contactNo, @emailId)";

SqlCommand cmd = new SqlCommand(sql, con);
cmd.Parameters.AddWithValue("@date", DateTime.Now);
cmd.Parameters.AddWithValue("@name", txtName.Text);
cmd.Parameters.AddWithValue("@gender", Gender);
cmd.Parameters.AddWithValue("@address", txtAddress.Text);
cmd.Parameters.AddWithValue("@contactNo", txtContact.Text);
cmd.Parameters.AddWithValue("@emailId", txtEmail.Text);

请参阅How does SQLParameter prevent SQL Injection?

还可以使用 App.config 来存储连接字符串：

<connectionStrings>
  <add name="ranjeet" 
       connectionString="Data Source=RANJEETMAURYA;Initial Catalog=Project;Integrated Security=True" 
       providerName="System.Data.EntityClient" />
</connectionStrings>

然后您就可以使用ConfigurationManager获得它。

还将连接和命令包装到using语句中以自动处理它们：

using (SqlConnection con = new SqlConnection(connectionString))
using (SqlCommand cmd = new SqlCommand(sql, con))
{
    // add parameters
    con.Open();
    cmd.ExecuteNonQuery();
}

Answer 2

为什么要将它转换为字符串只是将DateTime.Now发送到数据库并从数据库中检索它时使用此

retrieveDate = DateRetrieved.ToString（“MM / dd / yyyy hh：mm”）;

Answer 3

参考Sergey Berezovskiy的答案您也可以将参数传递为：

string sql = @"INSERT INTO CustomerDetails
               (Date, Name, Gender, Address, Contact_No, Email_ID)
               VALUES (@date, @name, @gender, @address, @contactNo, @emailId)";

SqlCommand cmd = new SqlCommand(sql);
cmd.Parameters.Add("@date", SqlDbType.Date).Value = DateTime.Now;
cmd.Parameters.Add("@name", SqlDbType.Varchar, 50).Value = txtName.Text;
cmd.Parameters.Add("@gender", SqlDbType.Varchar, 10).Value = Gender;
cmd.Parameters.Add("@address", SqlDbType.Varchar, 50).Value =txtAddress.Text;
cmd.Parameters.Add("@contactNo", SqlDbType.Varchar, 25).Value = txtContact.Text;
cmd.Parameters.Add("@emailId", SqlDbType.Varchar, 35).Value =txtEmail.Text;

winform c＃将数据（DateTime）插入SQL时出错

3 个答案: