public Tree</*WYSE*/IReadOnlyListDictionary> GetReportColumns(TraceTree parentTraceTree)
{
    var traceTree = parentTraceTree.AddChild();
    traceTree.RecordCodeMethodExecution(MethodBase.GetCurrentMethod());

    // It is good practice to decouple internal ids from externally used ones.
    // WYSE provides the means to do so.
    // However, for a better, easier to follow demo the ids are kept the same here.
    var customerTable = DemoTemplateAliasing.CreateAliasTemplate<CustomerTable>("Customer");
    
    var genericMappings = _genericMappingsRepository.All
        /*WYSE*/.DownstreamOf<CustomerTable>();

    var selectBuilder = new /*WYSE*/SelectBuilder<CustomerTable, Customer>(
        customerTable,
        genericMappings);

    var select = selectBuilder.Build();

    // Default implementation of the interface that only switches from the '.'
    // in external ids and the '_' in an expression's alias
    var aliasTranslator = new /*WYSE*/AliasTranslator();
    
    return select./*WYSE*/GetListDictionaryTree(aliasTranslator);
}

// Generate a report with all columns and no where clause.
public IReadOnlyList<Customer> GenerateFullReport(TraceTree parentTraceTree)
{
    var traceTree = parentTraceTree.AddChild();
    traceTree.RecordCodeMethodExecution(MethodBase.GetCurrentMethod());

    var customerTable = DemoTemplateAliasing.CreateAliasTemplate<CustomerTable>("Customer");
    
    var genericMappings = _genericMappingsRepository.All
        /*WYSE*/.DownstreamOf<CustomerTable>();

    var selectBuilder = new /*WYSE*/SelectBuilder<CustomerTable, Customer>(
        customerTable,
        genericMappings);
    // Alternatively...
    //var selectBuilder = new /*WYSE*/SelectBuilder(customerTable, typeof(Customer), genericMappings);

    var select = selectBuilder.Build();

    return _sqlExecuter.GetItemTrees<CustomerTable, Customer>(
        select,
        customerTable,
        genericMappings,
        parentTraceTree);
}

public IReadOnlyList<TItem> GetItemTrees<TList, TItem>(
    /*WYSE*/ISelect select,
    TList primaryList,
    IReadOnlyList</*WYSE*/GenericMapping> genericMappings,
    TraceTree parentTraceTree)
    where TList : /*WYSE*/IDbDataReaderConvertableList<TItem>
    where TItem : /*WYSE*/IKeyEquatable
{
    var traceTree = parentTraceTree.AddChild();
    traceTree.RecordCodeMethodExecution(MethodBase.GetCurrentMethod());

    using SqlConnection connection = _connectionFactory.Create();
    connection.Open();

    using SqlCommand command = connection.CreateCommand()
        // A WYSE Render context determines certain (overridable) render settings.
        // Here the context is SqlServer. More SQL flavors are supported.
        // A WYSE render builder is used for stringifying
        // the strongly typed SQL statements.
        /*WYSE*/.For(select,
            _renderContextFactory.Create(new DefaultQueryExecutionSettings()),
            _createRenderBuilder);

    try
    {
        using DbDataReader reader = command.ExecuteReader();

        var items = reader.GetItemTrees<TList, TItem>(select, primaryList, genericMappings)
            .ToList();

        traceTree.RecordDbCommandExecutionSuccess(
            command.CommandText,
            command.Parameters.ToDictionary(),
            items);

        return items;
    }
    catch (Exception exception)
    {
        traceTree.RecordDbCommandExecutionFailure(
            command.CommandText,
            command.Parameters.ToDictionary(),
            exception);

        return default;
    }
}

SELECT
    [Customer].[Id] [Customer_Id],
    [Customer].[FirstName] [Customer_FirstName],
    [Customer].[LastName] [Customer_LastName],
    [Customer].[DateOfBirth] [Customer_DateOfBirth],
    [Customer].[IsPreferred] [Customer_IsPreferred],
    [Customer].[HomeAddressId] [Customer_HomeAddressId],
    [Customer].[BillingAddressId] [Customer_BillingAddressId],
    [CustomerHomeAddress].[Id] [CustomerHomeAddress_Id],
    [CustomerHomeAddress].[City] [CustomerHomeAddress_City],
    [CustomerHomeAddress].[ZipCode] [CustomerHomeAddress_ZipCode],
    [CustomerHomeAddress].[Street] [CustomerHomeAddress_Street],
    [CustomerHomeAddress].[HouseNumber] [CustomerHomeAddress_HouseNumber],
    [CustomerHomeAddress].[HouseNumberAddition] [CustomerHomeAddress_HouseNumberAddition],
    [CustomerBillingAddress].[Id] [CustomerBillingAddress_Id],
    [CustomerBillingAddress].[City] [CustomerBillingAddress_City],
    [CustomerBillingAddress].[ZipCode] [CustomerBillingAddress_ZipCode],
    [CustomerBillingAddress].[Street] [CustomerBillingAddress_Street],
    [CustomerBillingAddress].[HouseNumber] [CustomerBillingAddress_HouseNumber],
    [CustomerBillingAddress].[HouseNumberAddition] [CustomerBillingAddress_HouseNumberAddition],
    [Purchase].[Id] [Purchase_Id],
    [Purchase].[CustomerId] [Purchase_CustomerId],
    [Purchase].[ProductId] [Purchase_ProductId],
    [Purchase].[Quantity] [Purchase_Quantity],
    [Purchase].[Date] [Purchase_Date],
    [Purchase].[DeliveryAddressId] [Purchase_DeliveryAddressId],
    [PurchasedProduct]._3e3e38037d5a4725a591b35b4176ebbe [PurchasedProduct_Id],
    [PurchasedProduct]._eaa34c7d88394ec18c25c6951257e777 [PurchasedProduct_Name],
    [PurchasedProduct]._1193c3f81e9a4384997711b04735d841 _306f1c7170425448d4bb917ae4047dec,
    [PurchasedProduct]._68fe5bf6a35e442cac2e66ccc08b2af6 _fac46b3db863bb9fe0b8e30faf239186,
    [PurchasedProduct]._015a1e9313c641c8a56b960ab682f0e8 [PurchasedProduct_Price],
    [PurchaseDeliveryAddress].[Id] [PurchaseDeliveryAddress_Id],
    [PurchaseDeliveryAddress].[City] [PurchaseDeliveryAddress_City],
    [PurchaseDeliveryAddress].[ZipCode] [PurchaseDeliveryAddress_ZipCode],
    [PurchaseDeliveryAddress].[Street] [PurchaseDeliveryAddress_Street],
    [PurchaseDeliveryAddress].[HouseNumber] [PurchaseDeliveryAddress_HouseNumber],
    [PurchaseDeliveryAddress].[HouseNumberAddition] [PurchaseDeliveryAddress_HouseNumberAddition]
FROM [Customer] [Customer]
LEFT JOIN [Address] [CustomerHomeAddress] ON ([Customer].[HomeAddressId] = [CustomerHomeAddress].[Id])
LEFT JOIN [Address] [CustomerBillingAddress] ON ([Customer].[BillingAddressId] = [CustomerBillingAddress].[Id])
LEFT JOIN [Purchase] [Purchase] ON ([Customer].[Id] = [Purchase].[CustomerId])
LEFT JOIN
(
    SELECT
        _900ce3356aa346688e1ccf5b85f501b1.[Id] _3e3e38037d5a4725a591b35b4176ebbe,
        _900ce3356aa346688e1ccf5b85f501b1.[Name] _eaa34c7d88394ec18c25c6951257e777,
        _6d9ad9bceed6451ea9bb786767722511.[From] _1193c3f81e9a4384997711b04735d841,
        ISNULL(_6d9ad9bceed6451ea9bb786767722511.[UpTo], '3000-01-01 00:00:00.000') _68fe5bf6a35e442cac2e66ccc08b2af6,
        _6d9ad9bceed6451ea9bb786767722511.[Price] _015a1e9313c641c8a56b960ab682f0e8
    FROM [Product] _900ce3356aa346688e1ccf5b85f501b1
    INNER JOIN [ProductPriceHistory] _6d9ad9bceed6451ea9bb786767722511 ON (_900ce3356aa346688e1ccf5b85f501b1.[Id] = _6d9ad9bceed6451ea9bb786767722511.[ProductId])
) [PurchasedProduct] ON
(
    ([Purchase].[ProductId] = [PurchasedProduct]._3e3e38037d5a4725a591b35b4176ebbe)
    AND
    ([PurchasedProduct]._1193c3f81e9a4384997711b04735d841 <= [Purchase].[Date])
    AND
    ([PurchasedProduct]._68fe5bf6a35e442cac2e66ccc08b2af6 > [Purchase].[Date])
)
LEFT JOIN [Address] [PurchaseDeliveryAddress] ON ([Purchase].[DeliveryAddressId] = [PurchaseDeliveryAddress].[Id])