Polyglot Notebook has an interesting feature that can share SQL query results directly from SQL to C#, this makes it useful as a scratchpad. The example code is below.

Cell 1 – Add NuGet packages for Polyglot, TabularDataResource, and DataFrame

#r "nuget: Microsoft.DotNet.Interactive.SqlServer, *-*"
#r "nuget: Microsoft.Data.Analysis"

Cell 2 – Connect to SQL Server and WideWorldImporters sample DB

#!connect mssql --kernel-name myDb1 "Server=(localdb)\LocalDB2025;Database=WideWorldImporters;Trusted_Connection=True;TrustServerCertificate=True;"

Cell 3 – Run the queries and set to customerData variable

#!sql-myDb1 --name customersData
SELECT TOP 3 *
FROM Sales.Customers WHERE CustomerName LIKE '%Toys%'

SELECT TOP 3 *
FROM Sales.Customers WHERE CustomerName NOT LIKE '%Toys%'

Cell 4 – Share to C# customerData

#!share --from sql-myDb1 customersData

foreach (var data in customersData)
{
    "Table".Display();
    foreach (IEnumerable<KeyValuePair<string, object>> row in data.Data)
    {
        // Row is a list instead of dictionary, need to search if want to display by column ID, e.g.
        // row.FirstOrDefault(x => x.Key == "CustomerID").Value.Display();
        
        foreach (KeyValuePair<string, object> field in row)
        {
            Console.Write($"{field.Key}: {field.Value} | ");
        }
        Console.WriteLine();
    }
}

Cell 5 – Another example of sharing customersData2 variable from SQL to C#

#!sql-myDb1 --name customersData2
SELECT TOP 3 CustomerID, CustomerName, BillToCustomerID, CustomerCategoryID, BuyingGroupID, PrimaryContactPersonID, AlternateContactPersonID, DeliveryMethodID, DeliveryCityID, PostalCityID, CreditLimit, CAST(AccountOpenedDate AS NVARCHAR(20)) AccountOpenedDate
FROM Sales.Customers WHERE CustomerName LIKE '%Toys%'

#!C#
#!share --from sql-myDb1 customersData2
var df = customersData2[0].ToDataFrame();
df.Display();

// If want to convert to DataTable
// df.ToTable().Display();

foreach (Microsoft.Data.Analysis.DataFrameRow row in df.Rows)
{
    // Access by column Name
    // row["CustomerID"].Display();
    
    for (int i = 0; i < df.Columns.Count; i++)
    {
        Console.Write($"{df.Columns[i].Name}: {row[i]} | ");
    }
    Console.WriteLine();
}

Note: The AccountOpenedDate column needs to be cast to nvarchar due to an error (Error: System.ArgumentOutOfRangeException: Specified argument was out of the range of valid values. at Microsoft.DotNet.Interactive.Formatting.TabularData.TabularDataResourceExtensions.ToDataFrame(TabularDataResource tabularDataResource)) in ToDataFrame(), so a workaround has been used.