在数据网格视图中将值从long转换为TimeSpan（带有SQL Server的C＃）

Question

I'm having a problem concerning my school project. I have a SQL Server table where I save flight duration (expressed in minutes), saved in ticks (in a bigint column).

In the program I have a datagridview where I load all the data from the SQL Server table and I'd now need to convert the "flight duration" column from ticks to time (something like HH:mm format), but I have no idea how would I achieve this.

My current code for converting the column looks like this, but the third line gives me error about converting 'object' to 'long'.

for (int i = 0; i < dgvTabla.RowCount; i++)
{
    var dt = new DateTime(dgvTabla[5, i].Value);
    string.Format("HH:mm", dt);
    dgvTabla[5, i].Value = dt;
}

Any ideas? Thanks!

Answer 1

If you want to convert your DURATION on the SQL Server side

Example

Declare @YourTable table (ID int,duration bigint)
Insert Into @YourTable values
 (1,600)
,(2,1365)

Select A.*
      ,AsTime   = cast(dateadd(MINUTE,duration,0) as time)
      ,AsString = format(dateadd(MINUTE,duration,0),'HH:mm')
 From  @YourTable A

Returns

ID  duration    AsTime              AsString
1   600         10:00:00.0000000    10:00
2   1365        22:45:00.0000000    22:45

Answer 2

You can call from Sql Server and display it directly to Grid. That will be easier to to do it. Below is the example

DECLARE @Time INT = 90
SELECT substring(CONVERT(char(8), DATEADD(MINUTE, @Time, ''), 108),0,6)

Hope that helps.