How to draw an ER diagram from a DFD

Question

I am doing my uni assignment and I need to draw an ER diagram out of a DFD which I have already done. What will be the entities in ER, only data stores from DFD or do I need to add something else? Thanks

Answer 1

If the ER diagram is intended to describe the conceptual data model, then every store and every dataflow (or the component of these) should find a place in the ER. A conceptual data model describes "what you talk about" and since you not only talk about stores, but also about dataflows, they need to be described.

If however, the ER is intended to become the basis for a database design, then the stores should be sufficient.

The first approach makes more sense, because a conceptiual data model and a DFD offer about the same level of abstraction. Making a step towards a database design is a whole level of detail further down.