How to compare all elements between Datatable and Array's months?

Question

I'd like to ask you guys for a question that helps from you.

I have a DataTable with months and amounts, as shown below, and an array named after all the months of the year. How could I build a structure that would return the months of the year with the quantities described in the DataTable along with the other months with the quantity in zeros?

Before

Mes Qt
Dec 6
Jan 2
Nov 2

After

Mes Qt
Jan 2
Fev 0
Mar 0
Abr 0
Mai 0
Jun 0
Jul 0
Ago 0
Set 0
Out 0
Nov 2
Dec 6

My code:

DataTable dt = new DataTable();
dt.Columns.Add("Data");
dt.Columns.Add("Quantidade");
dt.Rows.Add(new object[] { "Dec", 6 });
dt.Rows.Add(new object[] { "Jan", 1 });
dt.Rows.Add(new object[] { "Nov", 4 });

var monthsRange = Enumerable.Range(1, 12)
                .Select(e => e > 0 ? Convert.ToDateTime("20/" + e + "/2000").ToString("MMM", CultureInfo.GetCultureInfo("en-US")) : "")
                .ToArray();

Answer 1

Assuming you want the answer as List<anonymous> then I would convert the DataTable to a Dictionary and then use monthsRange to create the final List:

var monthsRange = Enumerable.Range(1, 12)
                .Select(e => new DateTime(2000,e,20).ToString("MMM", CultureInfo.GetCultureInfo("en-US")))
                .ToList();

var dtd = dt.AsEnumerable().ToDictionary(r => r.Field<string>("Data"), r => r.Field<string>("Quantidade"));

var ans = monthsRange.Select(Mes => new {
            Mes,
            Qt = dtd.TryGetValue(Mes, out var qt)
                    ? qt
                    : "0"
        })
        .ToList();