\begin{frame}
  \frametitle{ER Models vs. UML Class Diagrams}
  
  \begin{goal}{Entity Sets and Attributes}
    \begin{minipage}{.49\textwidth}
      \begin{center}
      \scalebox{.92}{
      \begin{tikzpicture}[every edge/.style={link}]
        \node[entity] (customer) {customer};
        \node[attribute] (id) [above left of=customer,node distance=1.7cm,shift={(-2mm,-3mm)}] {\key{id}} edge (customer);
        \node[attribute] (name) [above of=customer,node distance=1.3cm] {name} edge (customer);
        \node[attribute] (street) [left of=customer,node distance=2.1cm] {street} edge (customer);
        \node[attribute] (city) [below left of=customer,node distance=1.7cm] {city} edge (customer);
      \end{tikzpicture}
      }
      \end{center}
    \end{minipage}
    \begin{minipage}{.49\textwidth}
      \begin{center}
      \begin{tikzpicture}
      \umlclass{customer}{ 
        +id \umlkey \\
        +name \\
        +street \\
        +city 
        }{ 
        } 
      \end{tikzpicture} 
      \end{center}
    \end{minipage}
  \end{goal}
  
  \begin{itemize}
    \item In UML attributes are shown within the box of the entity set
          rather than as separate ellipses in ER models.
  \end{itemize}
\end{frame}