实体框架将字符串值转换为日期时间

Question

I have a table storing a list of dates & time (dd/MM/yyyy) in string format.

What I am trying to do is order the data by DateTime descending, the code below worked just fine but it just orders it by date (dd), So I have to convert it to Datetime to do the right job.

casesBindingSource.DataSource = db.casesSet
                                  .Where(x => x.casestatus == "شفيت")
                                  .OrderByDescending(c => c.dateofrecovery)
                                  .ToList();

Answer 1

try:

casesBindingSource.DataSource = db.casesSet
                                  .Where(x => x.casestatus == "شفيت")
                                  .OrderByDescending(c => DateTime.ParseExact(c.dateofrecovery, "dd/MM/yyyy", Nothing))
                                  .ToList();

Answer 2

Try this approach: .OrderByDescending(c => DateTime.ParseExact(c.dateofrecovery, "dd/MM/yyyy", CultureInfo.InvariantCulture))

Answer 3

Did you try first calling tolist and then running orderby. I know it is a bit inefficient, however it is worth giving a try.

casesBindingSource.DataSource = db.casesSet
                                  .Where(x => x.casestatus == "شفيت")
                                  .ToList()
                                  .OrderByDescending(c => DateTime.ParseExact(c.dateofrecovery, "dd/MM/yyyy",CultureInfo.InvariantCulture).Year)
                                  .ThenByDescending(c => DateTime.ParseExact(c.dateofrecovery, "dd/MM/yyyy", CultureInfo.InvariantCulture).Month)
                                  .ThenByDescending(c => DateTime.ParseExact(c.dateofrecovery, "dd/MM/yyyy", CultureInfo.InvariantCulture).Day);