Correct DateTime format in SQL Server CE?

Question

I have a C# DateTime class and wanted to know how I need to format it in a SQL Server CE query to insert it into the database, I was hoping to have both the date and time inserted in. Currently when I try variations thereof I get invalid format exceptions.

Current format I'm using is: dd/MM/yyyy, was hoping to do something like dd/MM/yyyy hh:mm:ss.

The way I'm trying to do the insert is like so:

 ( ( DateTime )_Value ).ToString( "dd/MM/yyyy hh:mm:ss" )

Obviously hh:mm:ss isn't working, if that isn't there dd/MM/yyyy executes successfully in the query.

I've tried a few formats including what I've found on google but none have worked so far...

Allieallied

Can you include your code so we can see what you have tried? – Spoondrift

Have you been able to insert other values into the database? getting any exceptions / errors? – Spoondrift

What is the field type you are inserting into? There is a difference between Date and DateTime in SQL Server. – Spoondrift

Hi @Jake1164, yes I've been able to add other values in to he database without issues, it's just when I try to add time things go wrong... – Allieallied

I'm using the DateTime field in the table... – Allieallied

What value is getting into the database? – Spoondrift

what is the Data Type defined as in the database ? I believe Jake has asked the same question..? – Mango

Try year-month-day with a '-' between them. time formatted the same way yyyy-MM-dd hh:mm:ss – Spoondrift

Answer 1

If you're worried about getting the format right at all, something has already gone seriously wrong. There are two things you need to do to correctly work with datetime values in any database, not just sqlce:

1. Make sure you're using a datetime type for the column (not a text type like varchar)
2. Make sure you're using a datetime parameter in a parameterized query, and not string concatenation.

If you do that, there is no formatting involved on your part. At all. Example:

 void SetDate(int recordID, DateTime timeStamp)
 {
    string SQL = "UPDATE [sometable] SET someDateTimeColumn= @NewTime WHERE ID= @ID";

    using (var cn = new SqlCeConnection("connection string here"))
    using (var cmd = new SqlCeCommand(SQL, cn))
    {
        cmd.Parameters.Add("@NewTime", SqlDbType.DateTime).Value = timeStamp;
        cmd.Parameters.Add("@ID", SqlDbType.Integer).Value = recordID;

        cn.Open();
        cmd.ExecuteNonQuery();
    }
} 

Never ever ever ever EVER use string manipulation to substitute values into sql queries. It's a huge no-no.

Eosinophil

+1 For pointing out to NEVER use string manipulation to store dates. – Spoondrift

+1 for lesson in NEVER using string manipulation in SQL queries. – Lipinski

can you do this: "UPDATE \@SomeTable SET \@SomeColumn ... etc" – Lipinski

Stack overflow wouldn't let me post the at symbols, hence the \ – Lipinski

Answer 2

Try the following format:

DateTime.Now.ToString("yyyy-MM-dd hh:mm:ss")

Spoondrift

Answer 3

Man, you do not need to convert string to DateTime.

Use a instance of a new DateTime and pass the date as parameter. Like this:

using (var ctx = new DBPreparoEntities())
{
    var _client = from p in ctx.Client
                     select new Client
                     {
                         data = new DateTime(2016,08,17),
                         dateconf = null,
                         scod_cli = p.Rua,
                         valorini = 7214.62m,
                     };
    return client.ToList();
}

don't use:

... data = DateTime.Parse("2016/12/10") // or other type convertions.

Sacrament

Answer 4

sorry this is in vb.net, but this is a method i use to convert from a CE date/time format:

Public Shared Function ConvertSqlDateTimeFormat(ByVal s As String) As String
    Dim theDate As New Text.StringBuilder
    Dim sTemp As String = ""
    Dim iIndex As Integer

    If s.Length > 8 Then
        'first we do the time
        iIndex = s.IndexOf(" ", System.StringComparison.OrdinalIgnoreCase)
        If iIndex > 0 Then
            sTemp = s.Substring(iIndex).Trim
            iIndex = sTemp.IndexOf(".", System.StringComparison.OrdinalIgnoreCase)
            If iIndex > 0 Then
                sTemp = sTemp.Substring(0, iIndex)
            End If
        End If

        'next the date
        theDate.Append(s.Substring(4, 2))
        theDate.Append("/")
        theDate.Append(s.Substring(6, 2))
        theDate.Append("/")
        theDate.Append(s.Substring(0, 4))
        theDate.Append(" ")
        theDate.Append(sTemp)
    End If
    Return theDate.ToString
End Function

Syl

The idea that you already have a method like this waiting to call is just wrong. String manipulation for sql data values has no place in secure code. – Eosinophil

Ok, where is the security hole then? Granted, i misunderstood the question and was focusing on translating date from the database to a datetime format, rather than the other way around, but if the data is already in the database, i'm not sure what the problem is? If a datetime.tryparse does not give the correct result, what other options do you have? – Syl

Answer 5

private void button1_Click(object sender, EventArgs e)
{
    var cnn1 ="";//connection string 
    SqlCeConnection cnn = new SqlCeConnection(cnn1);   
    datetime dt4 = DateTime.Today.Date.ToString("yyyyMMdd").trim();//format 
    var qry ="insert into tbl_test(User_Id, DateOfJoin)values (11,'" + dt4 + "')";
   
    cmd = new SqlCeCommand(qry, cnn);
   
    try
    {
        dr = cmd.ExecuteReader();
    }
    catch (Exception ex)
    {
        string sr = ex.Message;
        throw;
    }
}

Above code worked for me.

Synecdoche

a verbal explanation is often helpful for others – Law

//simply_pass _datetime _component _by converting to formatted string – Synecdoche