Lecture 4: From ER Diagrams to Relational Models

Title slideToday’s lecture reviewed the high-level conceptual language of ER diagrams and the more concrete structures of the relational model; followed by some recipes for translating from the first into the second. This isn’t always an exact match, and for any particular ER diagram we might go back to its original scenario description to decide how to best represent it as a relational model. Even so, this kind of step-by-step staging towards a fully formal representation is an effective route to capturing the subtleties of real-world systems.
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Lecture 3: The Relational Model

Title slideToday’s lecture expanded on last week’s material on Entity-Relationship modelling, and then set out the basic elements of the Relational Model for structured data. While ER diagrams provide a conceptual language for describing things as they are, and have applications outside databases for general organisation and management, the relational model is explicitly intended as a mathematically precise scheme for the computer-assisted creation and querying of large datasets.
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Lecture Slides Online

The slides for each Inf1-DA lecture are available in advance from the Lectures web page. On the day of the lecture you’ll see them marked “(Handout)” as that’s the version in the 3-up printed sheets. After the lecture itself I put up a blog post with a copy of the slides as displayed — sometimes that has a few more bits and pieces included.

Sometimes this means the page changes faster than web and browser caches expect: if you can’t get the slides for the day, try refreshing.

Link: List of lectures so far