Linq min date max date model querying
I’m unable to find out on how to get the min date and max date from a dictionary collection.
My model class looks like this:
Dictionary<string, IList<ErrorModel>> errorList public class ErrorModel { public string Date { get; set; } public int Total { get; set; } public string Description { get; set; } } What I want to do get the min date and max date of the collection.
Hope anyone can help me out
You can use Linq’s Enumerable.SelectMany to "flatten" the dictionary values, then use Min and Max methods:
var minDate = errorList.SelectMany(s => s.Value).Min(v => v.Date); var maxDate = errorList.SelectMany(s => s.Value).Max(v => v.Date); However, your Date property is defined as a string, you may not get the results you expect. Updating the definition to DateTime will give the correct results using Min/Max.
If you instead want to get the Min/Max per dictionary Key, you could project into an anonymous type:
var perKeyMinMax = errorList.Select(d => new { d.Key, Min = d.Value.Min(v => v.Date), Max = d.Value.Max(v => v.Date) }); foreach (var item in perKeyMinMax) { Console.WriteLine($"Key: {item.Key}, Min: {item.Min}, Max: {item.Max}"); } 
