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VisualizaçõesLINQ to SQL query not returning correct DateTime
I am trying to pull the most recent DateTime field from SQLite and it is returning the incorrect time.
Here's data in the database:
And here is my method to get the most recent DateTime via LINQ:
public string getLastSyncTime()
{
using (var db = new SQLite.SQLiteConnection(this.DBPath))
{
var query = db.Table<SyncAudit>()
.OrderByDescending(c => c.SyncTime)
.Select(c => c.SyncTime)
.FirstOrDefault();
return query.ToString();
}
}
The issue is that it is not returning the expected datetime. I am getting 1/1/0001 12am:
What am I doing wrong?
EDIT: THis is the provider being used, per request: https://components.xamarin.com/view/sqlite-net
Edit 2: Requested SyncAudit Class:
class SyncAudit
{
public string Server { get; set; }
public string Database { get; set; }
public DateTime SyncTime { get; set; }
public int Successful { get; set; }
}
3 Respostas
Responde à pergunta0
Change
public DateTime synctime{ get; set; }
to:
public DateTime? synctime { get; set; }
Hope it will helps. What happens is DateTime is NOT NULL data type and it enforces to put a default value there (01/01/0001) to make sure that non-null date will be submitted.Don't know whether it can be an issue..try and check
0
I looked at all possible scenarios when this result can happen. There is only one logical explanation to your problem. Your
db.Table<SyncAudit>()
is an empty collection and when you select
db.Table<SyncAudit>()
.OrderByDescending(c => c.SyncTime)
.Select(c => c.SyncTime)
.FirstOrDefault();
it will naturally return you default value of the DateTime. Check your database connection and make sure it works first.
0
To diagnose what the problem is, go back to basics. Change the LINQ into a foreach loop to iterate over all the records, and find the biggest value. Now step through the code (because I suspect that won't do what you expect either) and you'll see what's going wrong. Then tell us what was wrong.