Question

I’ve a Datatable with about 156K and I want to make 6 Datatable and divide the records to each of them like table1 will hold rows from 0 to 30k and table 2 will hold rows from 30k1 to 60k and so on.

the big table is ordered with numerical column that goes from 0 to 14

any suggestions on how to do this without looping?

Answer 1

You can use LINQ’s GroupBy:

Testdata:

Dim tbl1 = New DataTable
tbl1.Columns.Add("ID", GetType(Int32))
tbl1.Columns.Add("Text", GetType(String))
For rowIndex As Int32 = 1 To 156000
    tbl1.Rows.Add(rowIndex, "Row " & rowIndex)
Next

Split into multiple tables:

Dim tableCount = 6 
Dim divisor = tbl1.Rows.Count / tableCount ' needed to identify each group '
Dim tables() As DataTable = tbl1.AsEnumerable().
        Select(Function(r, i) New With {.Row = r, .Index = i}).
        GroupBy(Function(x) Math.Floor(x.Index / divisor)).
        Select(Function(g) g.Select(Function(x) x.Row).CopyToDataTable()).
        ToArray()

Note that this will split them into tables with 26000 rows in each since 156000 / 6 = 26000.