How to get a value from a date from a table with date range?

Question

I have a table with the value of a range of dates. If I input a date then it should look that date within a date range in the table and give me a value. I am working in C#.

DateFrm   |DateTo    |ivalue
----------|----------|-----
2019-01-01|2019-02-01|10
2019-02-02|2019-03-01|11
2019-03-02|2019-04-01|12

If I enter a date eg 2019-02-09 then it should return me value 11. Please help me to find my values in C#. Thank you.

I was trying something like.. but never get it sorted.

if(obj.mytable.rows.count>0) {foreach } ...

Answer 1

Suppose that dt is your DataTable:

string example = "2019-02-09";
DataRow[] results = dt.Select($"DateFrm <= #{example}# AND DateTo >=#{example}#");
Console.WriteLine(results[0]["ivalue"]);

Output:

11

Answer 2

Run a loop for the rows to check the condition as specified below

  for (int i1 = 0; i1 < table.Rows.Count; i1++)
            {
                DataRow row = table.Rows[i1];
                var datefrm = DateTime.Parse(row["DateFrm"].ToString());
                var dateto = DateTime.Parse(row["DateTo"].ToString());
                if (inputDate >= datefrm && inputDate <= dateto)
                {
                    return row["ivalue"];
                }
            }

Answer 3

It's quite simple using LINQ.

void Main()
{
    var lst= new List<DateRange>();
    var dr = new DateRange(new DateTime(2019, 1, 1),new DateTime(2019, 2, 1),10);
    lst.Add(dr);
    dr = new DateRange(new DateTime(2019, 2, 2), new DateTime(2019, 3, 1), 11);
    lst.Add(dr);
    dr = new DateRange(new DateTime(2019, 3, 2), new DateTime(2019, 4, 1), 12);
    lst.Add(dr);

    var searchFor = new DateTime(2019, 2, 9);

    var res = (from x in lst
              where x.DateFrm <= searchFor
                 && searchFor <= x.DateTo
             select x.IValue).Single();
    Console.WriteLine($"result:{res}");
}

public class DateRange
{
    public DateTime DateFrm { get; set; }
    public DateTime DateTo  { get; set; }
    public int      IValue  { get; set; }
    public DateRange(DateTime dateFrm, DateTime dateTo, int iValue)
    {
        DateFrm = dateFrm;
        DateTo  = dateTo;
        IValue  = iValue;
    }
}

Answer 4

You could query your DataTable with LINQ, using the extension method AsEnumerable . To use this method, a reference to the System.Data.DataSetExtensions assembly is required.

CultureInfo.CurrentCulture = CultureInfo.InvariantCulture;
var dt = new DataTable();
dt.Columns.Add("DateFrm", typeof(DateTime));
dt.Columns.Add("DateTo", typeof(DateTime));
dt.Columns.Add("ivalue", typeof(int));
dt.Rows.Add("2019-01-01", "2019-02-01", 10);
dt.Rows.Add("2019-02-01", "2019-03-01", 11);
dt.Rows.Add("2019-03-01", "2019-04-01", 12);

var searchFor = new DateTime(2019, 2, 9);

DataRow[] results = dt.AsEnumerable().Where(row =>
    searchFor >= row.Field<DateTime>("DateFrm") &&
    searchFor < row.Field<DateTime>("DateTo")).ToArray();

foreach (var result in results)
    Console.WriteLine(String.Join(", ", result.ItemArray));

Output:

02/02/2019 00:00:00, 03/01/2019 00:00:00, 11

Answer 5

I am sorry that I couldn't make my question easier, potentially I haven't mentioned about I am using LINQ.

I have created a procedure after getting help from here.

where DateFrm<=mysearchdate and DateTo<=mysearchdate

Later in the flow, I have called that in the code

var vl = (from s in obj.st_getiValueSearch(mysearchdate.Value) select s.ivalue).Single();

Thanks again for prompt help.