ExcelからSQLおよびDataGridへのデータ変換はDataTableを介して行います。

VB C#

using IronXL;
using System;
using System.Data;

// Supported for XLSX, XLS, XLSM, XLTX, CSV and TSV
WorkBook workBook = WorkBook.Load("sample.xlsx");

// Select default sheet
WorkSheet workSheet = workBook.DefaultWorkSheet;

// Convert the worksheet to DataTable
DataTable dataTable = workSheet.ToDataTable(true);

// Enumerate by rows or columns first at your preference
foreach (DataRow row in dataTable.Rows)
{
    for (int i = 0 ; i < dataTable.Columns.Count ; i++)
    {
        Console.Write(row[i]);
    }
}

Imports IronXL
Imports System
Imports System.Data

' Supported for XLSX, XLS, XLSM, XLTX, CSV and TSV
Private workBook As WorkBook = WorkBook.Load("sample.xlsx")

' Select default sheet
Private workSheet As WorkSheet = workBook.DefaultWorkSheet

' Convert the worksheet to DataTable
Private dataTable As DataTable = workSheet.ToDataTable(True)

' Enumerate by rows or columns first at your preference
For Each row As DataRow In dataTable.Rows
	For i As Integer = 0 To dataTable.Columns.Count - 1
		Console.Write(row(i))
	Next i
Next row