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Draw an E-R diagram for the following situation:

A laboratory has several chemists who work on one or more projects. A project may involve one to many chemists. Chemists may also use certain kinds of equipment on each project. Attributes of CHEMIST include Employee_ID (identifier), Name, and Phone_no. Attributes of PROJECT include Project_ID (identifier) and Start_Date. Attributes of EQUIPMENT include Serial_no. and Cost. The organization wants to record Assign_Date – that is, the date when a chemist is assigned to a specified project.

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mjassim

Answer:

Hi there! This question is good to check your knowledge of entities and their relationships. The diagram and explanation are provided below.

Explanation:

The entity relationship diagram for the association between the entities according to the description in the question is drawn in the first attachment. We can further simplify the relationship by removing this many to many relationship between "Chemists" and "Projects" by adding another entity called "Worklist" as detailed in second attachment.

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