Imports System

Public Module Module1

    Public Sub Main()

        Dim eventos = "table1"

        Dim upperBounds = 8

        Dim unions(upperBounds - 1) As String

        For index = 1 To upperBounds

            unions(index - 1) = "SELECT Previaso_Nasc_" & index & "_Ovo As ColumnZ, Viveiro_N FROM " & eventos & " WHERE CDate(Previaso_Nasc_" & index & "_Ovo) >= ?"

        Next

        Dim sql = String.Join(Environment.NewLine & "UNION ALL" & Environment.NewLine, unions)

        Console.WriteLine(sql)

    End Sub

End Module