Following section demonstrates using <b>GROUP BY</b> clause.
<sample>
    <pre lang="c#">
		// Table Aliases
        var t0 = new Orders().AsQueryable();

		// Query
        var query = Odb.SQL.Select(x => 
                        x.From(t0)
                        {{hl}}.GroupBy(t0.EmployeeID){{/hl}}
                         .Fields(
                                t0.EmployeeID, 
                                 {{hl}}x[t0.OrderID].MAX().AS("LastOrderId"){{/hl}}
                            )
                    );
    </pre>
    <output>
        SELECT <br />
        <span class="d-block ps-5">
            t0.EmployeeID,<br />
            <hlb>MAX(t0.OrderID) AS LastOrderId</hlb>
        </span>
        FROM [Orders] AS t0 <br />
        <hlb>GROUP BY t0.EmployeeID</hlb>
    </output>
    <fiddle>pWeo94</fiddle>
</sample>