从字符串转换日期和/或时间时如何修复转换失败

Question

con.open();
SqlCommamd comm = new SqlCommand("Insert into Debt_Tab values('"+Textbox1.text+"')",con);
comm.ExecuteNonQuery();

Textbox1 I is declared as a DateTime in my Sql table.

Answer 1

There are a lot of different ways to format a date. To be sure that the database gets the correct format I suggest that you parse the date by specifying a culture.

For desktop applications, this is easy since the OS is configured for a specific format, while for web applications the user uses their own preferred format (unless you have specified something else).

To parse using the OS culture:

var date = DateTime.Parse(Textbox1.Text)

To parse using a specific culture:

var swedish = new CultureInfo("sv_se");
var date = DateTime.Parse(TextBox1.Text, swedish);

Another thing. There is something seriously wrong with your code. It's vulnerable to SQL injection attacks. You need to use a parameterized query instead.

var cmd = new SqlCommand(con);
cmd.CommandText = "Insert into Debt_Tab values(@date)";
cmd.Parameters.AddWithValue("date", date);
cmd.ExecuteNonQuery();

Answer 2

使用这个希望这会奏效

DateTime.ParseExact(Textbox1.text, "MM/dd/yyyy", CultureInfo.InvariantCulture)

Answer 3

Try this:-

Convert.ToDateTime()

example:-

con.open();
SqlCommamd comm = new SqlCommand("Insert into Debt_Tab values('"+ Convert.ToDateTime(Textbox1.text).ToString("mm/dd/yyyy") +"')",con);
comm.ExecuteNonQuery();

Answer 4

Try the following way to validate the date

bool res;
  DateTime Date;
  string myDate = Textbox1.text;
  res = DateTime.TryParse(myDate, out Date);
  if(res)
  {
   // Validation or conversion success and result will be available in Date variable
  }
  else 
  {
     // conversion Fail
  }