Sorting a DataTable using LINQ - linq

Question

I have a DataTable which has the following structure.
StartDate (Type DateTime)
EndDate (Type DateTime)
Description (Type Text)
What I need to check is if the dates overlap or not, i.e., if the Start Date of 1 item is less than the EndDate of the previous item.
Here is the code I wrote.
NB: I already have checks to ensure that for each record, the Start Date has to be lesser than the End Date
dtDates.DefaultView.Sort = "StartDate ASC"; //Sort the DataTable based on the Start Dates
if(dtDates.Rows.Count > 1) //Check only if more than 1 Date is specified
{
for (int i = 1; i < dtDates.Rows.Count; i++)
{
if(TypeConvert.ToDate(dtDates.Rows[i]["StartDate"] < TypeConvert.ToDate(dtDates.Rows[i-1]["EndDate"])
{
retVal = true;
currentRow = i;
break;
}
}
}
The above code works fine.
But now, I want to implement it using LINQ
So, here is the code I am trying to attempt.
How can I do the whole comparison using LINQ?
public static bool CheckIfDatesOverlap(DataTable dataTable)
{
bool retVal = false;
int currentRow = 0;
List<DataRow> listDates = (from DataRow dgv in dataTable.Rows
select dgv).OrderBy(x => x[StartDate]).ToList();
if (listDates.Count > 1) //Perform Comparision only if more than 1 row is present
{
for (int i = 1; i < listDates.Count; i++)
{
if (TypeConvert.ToDateTime(listDates[i][StartDate]) < TypeConvert.ToDateTime(listDates[i][EndDate]))
{
retVal = true; //There are duplicates, hence return true
currentRow = i;
break;
}
else
{
//Do nothing as dates do not overlap
}
}
}
else
{
retVal = false; //As there is only 1 row, return false
}
if (retVal)
{
string message = "Dates Overlap";
//Display message
}
return retVal;
}

Answer 1

If you use SelectWithPrevious described here then you can write the following:
bool datesOverlap = table.Rows
.Cast<DataRow>()
.SelectWithPrevious((current, previous) => new
{
PreviousEndDate = (DateTime)previous["EndDate"],
StartDate = (DateTime)current["StartDate"]
})
.Any(x => x.StartDate < x.PreviousEndDate);