\begin{frame}
  \frametitle{Joins}
  
  A \emph{join} needs to be explicitly specified in the \sql{where} clause:
  \begin{tcenter}
    \begin{code}{.9\textwidth}{}
      \small
      \BUseVerbatim{query}
    \end{code}
  \end{tcenter}

  \tableStudentsResults  
  \pause

  \begin{quiz}{\textwidth}{Output of this query?}
    \small
    \BUseVerbatim{wrong}
  \end{quiz}
  % every name 3 times
\end{frame}