\begin{frame}
  \frametitle{Having}

  \structureAll
  \medskip
  
  \begin{code}{\textwidth}{Which Students got at least 18 homework points?}
    \small
    \pause
    \BUseVerbatim{query}
  
    \medskip
    \begin{tcenter}
    \colorbox{rellight}{%
      \ttfamily\footnotesize
      \begin{tabular}{|r|r|}
        \hline
        \hd{first} & \hd{last} 
        \\
        \hline
        George & Orwell \\
        Elvis & Presley \\
        \hline      
      \end{tabular}%
    }
    \end{tcenter}
  \end{code}
  \pause
  
  \begin{goal}{}
    \begin{itemize}
      \item The \sql{where} clause refers to single tuples.
      \item The \sql{having} clause applies to entire groups.
    \end{itemize}
  \end{goal}
\end{frame}