CODEWITHSUNDEEP
c#sql-serverdatetimesqldatareaderdatetime2
Dennie
Dennie

Reputation: 753

DateTime2 to C# DateTime with SqlDataReader

I realize this might be a dupe, but I've spent hours searching for the answer and can't seem to find it.

I'm currently creating a web API that retrieves concert data.

I have a SQL Server table that holds a start and end date, both as a datetime2 type. I've inserted the dates in this format and they don't cause any problems when viewing the database:

2015-10-08T20:00:00.0000000+01:00

My model:

public class Concert
{
    public int Id { get; set; }
    public string Name { get; set; }
    public int LocationId { get; set; }

    [Column(TypeName = "DateTime2")]
    public DateTime Start { get; set; }

    [Column(TypeName = "DateTime2")]
    public DateTime End { get; set; }

    public string Description { get; set; }
    public string Url { get; set; }
}

And my method in the class that brings up my database data:

    public List<Concert> getAll() 
    {
        List<Concert> concerts = new List<Concert>();

        SqlConnection connection = CasWebAPIdb.getConnection();
        String selectAll = "SELECT ConcertId, ConcertName, ConcertLocationId FROM dbo.Concerts";
        SqlCommand selectCommand = new SqlCommand(selectAll, connection);

        try
        {
            connection.Open();
            SqlDataReader reader = selectCommand.ExecuteReader();
            var isoDateTimeFormat = CultureInfo.InvariantCulture.DateTimeFormat;

            while (reader.Read())
            {
                //Debug.WriteLine("lol: " + reader["ConcertEnd"].GetType());

                Concert concert = new Concert();

                concert.Id = (int)reader["ConcertId"];
                concert.Name = reader["ConcertName"].ToString();
                concert.LocationId = (int)reader["ConcertLocationId"];
                concert.Start = (DateTime)reader["ConcertStart"];
                concert.End = (DateTime)reader["ConcertEnd"];

                concerts.Add(concert);
            }
        }
        catch (SqlException ex)
        {
            throw ex;
        }
        finally
        {
            connection.Close();
        }
        return concerts;
    }
}

I get this error when debugging:

An exception of type 'System.IndexOutOfRangeException' occurred in System.Data.dll but was not handled in user code

I have tried a lot of things and followed a lot of examples and codes, but I can't seem to convert this properly. Does anybody have an idea?

solution

I forgot to add the 'concertStart' and 'concertEnd' to my query. Problem solved, thanks!

Upvotes: 8

Views: 10219

Answers (4)

Vishal
Vishal

Reputation: 615

Anyone who wants to restore SQL DateTime2 to DateTime correctly including 'Kind=Utc'

(DateTime)reader["ConcertEnd"].ToUniversalTime();

otherwise DateTime may struggle to workout what timezone the date is from

Upvotes: 0

StuartLC
StuartLC

Reputation: 107367

The problem is that in your select, you only return 3 of the columns needed:

 String selectAll = "SELECT ConcertId, ConcertName, ConcertLocationId ...";

Whereas in your reader, you attempt to scrape 5 columns:

concert.Id = (int)reader["ConcertId"];
concert.Name = reader["ConcertName"].ToString();
concert.LocationId = (int)reader["ConcertLocationId"];
concert.Start = (DateTime)reader["ConcertStart"];
concert.End = (DateTime)reader["ConcertEnd"];

Hence the IndexOutOfRangeException. Either select all columns, or remove the extraneous ones from the reader.

The issue isn't related to Sql DateTime2 vs .Net DateTime - ADO will bind these just fine.

Upvotes: 1

marc_s
marc_s

Reputation: 755321

First of all, if you want to read the value of ConcertStart and ConcertEnd, you'd have to include them in your SELECT!!$

string selectAll = @"SELECT ConcertId, ConcertName, ConcertLocationId,
                            ConcertStart, ConcertEnd     <<--- add these!! 
                     FROM dbo.Concerts";

Try this:

while (reader.Read())
{
    Concert concert = new Concert();

    concert.Id = (int)reader["ConcertId"];
    concert.Name = reader["ConcertName"].ToString();
    concert.LocationId = (int)reader["ConcertLocationId"];
    concert.Start = reader.GetFieldValue<DateTime>(reader.GetOrdinal("ConcertStart"));
    concert.End = reader.GetFieldValue<DateTime>(reader.GetOrdinal("ConcertEnd"));

    concerts.Add(concert);
}

I have no trouble at all reading out a DATETIME2(3) value from the SQL Server database using

reader.GetFieldValue<DateTime>(reader.GetOrdinal("ConcertEnd"));

Does that work for you?

Upvotes: 8

stefankmitph
stefankmitph

Reputation: 3306

I'd do it with an extension method I found here

public static DateTime ToDate(this string input, bool throwExceptionIfFailed = false)
{
    DateTime result;
    var valid = DateTime.TryParse(input, out result);
    if (!valid)
        if (throwExceptionIfFailed)
            throw new FormatException(string.Format("'{0}' cannot be converted as DateTime", input));
   return result;
}

Convert your data like this:

concert.Start = reader["ConcertStart"].ToString().ToDate();
concert.End = reader["ConcertEnd"].ToString().ToDate(true); //throws an exception if it fails

Hope this helps!

Upvotes: 0

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