29/123
\begin{frame}
  \frametitle{The Relational Model}
  
  \begin{goal}{Overview}
    \bigskip
    \begin{enumerate}
      \item Relational Model Concepts: Schema, State \\[2ex]
      \item \alert{Null Values} \\[2ex]
      \item Constraints: General Remarks \\[2ex]
      \item Key Constraints \\[2ex]
      \item Foreign Key Constraints 
    \end{enumerate}
    \bigskip
  \end{goal}
\end{frame}