\begin{frame}
  \frametitle{UML Class Diagram}
  
  \begin{block}{UML class diagrams}
    \begin{itemize}
      \item similar to ER diagrams:\\
          \emph{entities/relationships} $\implies$ \emph{classes/associations}
    \end{itemize}
  \end{block}
  \medskip
  
  \begin{exampleblock}{Example schema as UML class diagram}
    \begin{center}
    \begin{tikzpicture}
    \umlclass{Customers}{ 
      +id \\
      +name \\
      +street \\
      +city 
      }{ 
      } 
    \umlclass[x=7]{Accounts}{ 
      +account-number \\
      +balance
      }{ 
      } 
    \umlassoc[arg1=1,pos1=0.1,arg2=0..*,pos2=.9,name=assoc]{Customers}{Accounts} 
    \node [ao=assoc-1] {deposits $\triangleright$ $\quad$};
    \node [bo=assoc-1] {$\triangleleft$ depositor $\quad\quad$};
%     \umlassoc[attr1=mult1|arg1, attr2=mult2|arg2]{customer}{account} 
    \end{tikzpicture} 
    \end{center}
  \end{exampleblock}
  \bigskip
  
  Conceptual design is usually converted to the relational model.
\end{frame}

\theme{Summary}