Import and Export Data

OfficeIMO.Excel reads and writes the shapes .NET code already uses: typed objects, DataTable, and IDataReader. Header names map to property names, and cell values keep their types (numbers, dates, booleans) instead of becoming text.

Write objects or a DataTable to a sheet

C#

using System.Data;
using OfficeIMO;
using OfficeIMO.Excel;

var table = new DataTable("Servers");
table.Columns.Add("Name", typeof(string));
table.Columns.Add("Cores", typeof(int));
table.Columns.Add("Patched", typeof(DateTime));
table.Rows.Add("app-01", 8, new DateTime(2026, 10, 2));
table.Rows.Add("db-01", 16, new DateTime(2026, 9, 28));

using var book = ExcelDocument.Create("Inventory.xlsx");
book.AddSheet("Servers").AddTable(table, new OfficeTableOptions { Name = "Servers" });
book.AddSheet("Owners").AddTable(new[] {
    new { Team = "Platform", Owner = "Adele Vance" },
    new { Team = "Data", Owner = "Alex Wilber" }
});
book.Save();

PowerShell

Get-Service | Select-Object Name, Status, StartType |
    Export-OfficeExcel -Path .\Services.xlsx -Sheet Services -TableName Services

Read rows as objects or a DataTable

RowsAs<T> maps by header name. ToDataTable returns a typed DataTable for code that binds to one.

C#

using System.Data;
using OfficeIMO.Excel;

using var book = ExcelDocument.Load("Inventory.xlsx");

foreach (Server server in book["Servers"].RowsAs<Server>()) {
    Console.WriteLine($"{server.Name}: {server.Cores} cores");
}

DataTable owners = book["Owners"].ToDataTable();
Console.WriteLine($"{owners.Rows.Count} owners");

record Server(string Name, int Cores, DateTime Patched);

PowerShell

$rows = Import-OfficeExcel -Path .\Inventory.xlsx -Sheet Servers
$rows | Where-Object Cores -ge 16

Stream a sheet through IDataReader

ExcelDocument.OpenReader returns an ExcelWorkbookDataReader (a DbDataReader), so rows can flow into SqlBulkCopy or any API that accepts a data reader without loading the workbook model.

C#

using System.Data;
using OfficeIMO.Excel;

using ExcelWorkbookDataReader reader = ExcelDocument.OpenReader("Inventory.xlsx",
    new ExcelReaderOptions { SheetName = "Servers" });

while (reader.Read()) {
    string name = reader.GetString(reader.GetOrdinal("Name"));
    Console.WriteLine(name);
}

Write a database result to Excel

Pass the IDataReader from a database command straight to the streaming writer. Rows are written as they are read.

C#

using System.Data;
using OfficeIMO.Excel;

static void ExportOrders(IDataReader orders, string path) {
    using ExcelWorkbookWriter writer = ExcelDocument.CreateWriter(path);
    writer.WriteTable("Orders", orders);
}

Convert between CSV and Excel

Install OfficeIMO.Excel.Csv to import a CSV file as a typed table, or save a sheet as CSV. See Convert CSV to Excel for options.

C#

using OfficeIMO.Excel;
using OfficeIMO.Excel.Csv;

using var book = ExcelDocument.Create();
ExcelCsvImportResult imported = book.ImportCsvFile("sales.csv");
book[imported.SheetName].SaveAsCsv("sales-roundtrip.csv");
book.Save("sales.xlsx");

CLI

officeimo tabular convert sales.csv sales.xlsx
officeimo tabular convert Inventory.xlsx servers.csv --sheet Servers

Limits and reference

Limits: see the Excel package row and the Excel CSV adapter row.

Reference: OfficeIMO.Excel API · OfficeIMO.Excel.Csv API