# Miscellaneous > Database Design >  Database ERDs

## ACarmon02

Morning all,


I have been given a small project at work to create a database from scratch which is basically to log incidents.

I have identified the information which I need to record but am struggling to break this down into the required tables and attributes.

*Information to be stored.*
Unique Incident Number
Year of incident
Month of incident
Day of incident (Mon, Tue etc)
Time of incident
Location of incident (there are 100 potential locations)
Severity of incident (Low / Medium / High)

All of the examples on 'how to create and ERD' always use the customer / order / product scenario which I understand, but i cant apply that model to this set of requirements.

Once created, I need to be able to say where the most events have occurred / where no events have occurred / on what month or day do most events occur etc.

Any help would be awesome....thanks.

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## skhanal

You can create tables for incident, location and severity. All date / time could be one field.

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## ACarmon02

Slide1.JPG

I have amended my schema diagram to create 2 tables.
I know what data types and values I need to set but im not quite sure how to set them.
In particular how do I set it so that only 'x', 'y' or 'z' can be entered?

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## skhanal

You can create constraints on each column to limit the type of value. The physical model depends on the type of database system you are using.

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