\begin{frame} \frametitle{Common Errors} \structureAll \smallskip \begin{code}{\textwidth}{Find those students who have neither submitted a homework nor participated in any exam} {\small \BUseVerbatim{query} } \end{code} \smallskip \begin{quiz}{\textwidth}{What is the error in this query?} What is the output of this query? Fix the query. \end{quiz} %% (1) %% Yes, reference to sid in subquery is OK (but it references sid of %% Students since there is not sid in Exercises!) %% (2) %% empty (subquery is correlated) %% (3) %% Replace Exercises by Results (and optionally introduce tuple %% variables to make intent explicit). \end{frame}