convert datatable column values double[]

Question

Hi,

My datatable has one column and 5 rows which i am binding from database.

i want to get the values from datatable and assign it to double array. is it possbile to do this uing LINQ? i don't wnat to loop the datatable and cast. 

Any sample code please 

 

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loving dotnet

Answer 1

        static void Main(string[] args)
        {
            DataSet ds = new DataSet();
            ds.Tables.Add(new DataTable());

            DataColumn dc2 = new DataColumn("Value");
            dc2.DataType = System.Type.GetType("System.Double");
            ds.Tables[0].Columns.Add(dc2);

            DataRow r1 = ds.Tables[0].NewRow();
            r1["Value"] = 75.8300000000;
            ds.Tables[0].Rows.Add(r1);

            DataRow r2 = ds.Tables[0].NewRow();
            r2["Value"] = 76.6800000000;
            ds.Tables[0].Rows.Add(r2);

            DataRow r3 = ds.Tables[0].NewRow();
            r3["Value"] = 79.8787870000;
            ds.Tables[0].Rows.Add(r3);

            var query2 = ds.Tables[0].AsEnumerable().Select(x => x.Field<Double>("Value"));


            Console.ReadKey();
        }

This will accomplish what you need it to do you just need to define that column as type double to avoid casting.

Answer 2

Hi IdahoSixString,

thanks for your reply

i must be in the position to cast because from database it comes as string. so  i have to cast. can you please show me the code where i can cast and convert to double array from your sample

---

loving dotnet

Answer 3

Hi,

you can use Convert.ToDouble with an appropriate CultureInfo:

    var table = new DataTable("Table1");
    table.Columns.Add("column1", typeof(string));
    table.Rows.Add("12345");
    table.Rows.Add("123.45");
    table.Rows.Add("-123.45");
    table.Rows.Add("1.23E3");
    table.Rows.Add("4.56E-3");

    double[] result = table.AsEnumerable()
            .Select(row => Convert.ToDouble(row.Field<string>("column1"), System.Globalization.CultureInfo.InvariantCulture)).ToArray();
    
    Console.WriteLine(String.Join(",", result));

Regards, Elmar

Answer 4

var query2 = ds.Tables[0].AsEnumerable().Select(x => Convert.ToDouble(x.Field<String>("Value"))).ToArray();