ER exercise: Papers

Below is an ER model for a research group in chemistry that we're going to interpret. It is mainly concerned with keeping track of papers and the reactions they discuss.

Questions you should answer:

- List the entity types.
- List the relationships.
- What's the maximum number of papers an author can write?
- What's the minimum number of papers a paper can refer to?
- What's the minimum number of papers a paper can be referred to by?
- Are there any people who didn't write papers in the
*Author*table? - Can we say
*exactly*how many journals an issue can be in? - What's the maximum number of journals a paper can be in?
- Can we say
*exactly*how many journals a paper can be in? - What's the minimum number of papers a journal can contain?
- What's the minimum number of authors for all the papers in one journal?
- Does a paper have to be referred to by another paper?
- How many tables would be needed for this database?
- How many primary keys would be needed for this database?
- List all the tables in which a foreign key referring to
*Issue*appears. - List all the tables in which a foreign key referring to
*Paper*appears.

page revision: 3, last edited: 19 Aug 2008 00:29