\begin{frame}
  \frametitle{Integrity Constraints in SQL}
  
  \begin{goal}{}
  The SQL \sql{create table} allows the following \textbf{constraints}:
  \smallskip
  \begin{itemize}
  \item \emph{Not Null}: \\
    \remark{No value in this column can be the null value.}
  
  \item \emph{Key constraints:} \\
    \remark{Each key value can appear once only.}

  \item \emph{Foreign keys constraints:}\\
    \remark{Values in a column must also appear as key values in another table.}

  \item \emph{Check constraints}:\\
    \remark{%
      Column values must satisfy a given predicate.\\
      SQL allows for inter-column \sql{CHECK} constraints.
    }
  \smallskip
  \end{itemize}
  \end{goal}
  \pause\medskip
  
  \begin{code}{\textwidth}{}
  \small
  \BUseVerbatim{createtable}
  \end{code}
  \bigskip
\end{frame}