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Projects(Project_id,Name,description,due_date) Emp_projects(Project_ID,Emp_id) Tasks(task_id,name,description,status,due_date,completed_date,Emp_id,Project_id)

An employee will work on none or many projects An employee will be assigned to one or many tasks related to the project A task will have only one employee assigned to it

philipxy
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sarah
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    Can you share some of your own attempts to this question? – Nico Haase Apr 22 '20 at 06:11
  • Right now you are just asking for us to rewrite your textbook with a bespoke tutorial & do your (home)work & you have shown no research or other effort. Please see [ask], hits googling 'stackexchange homework' & the voting arrow mouseover texts. Show the steps of your work following your textbook with justification & ask 1 specific question re the first place you are stuck. PS You don't give info needed to answer the question. So you don't seem to understand the basics. PS Please before you post look at the formatted version of your post below the edit box. Read edit help re line breaks. – philipxy Apr 22 '20 at 06:45

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Assuming that there are no multi-valued columns and all the values in a column are in same domain, it is in 1-NF.

There seems to be no partial dependency either. i.e. None of the non-prime key depends on only part of the composite prime-key. There isn't even a table here where it would be possible since only the Emp_projects seems to have a composite candidate key which also happens to be only keys in it. So, we can say it is in 2-NF.

For Projects, I assume that None of the non-primary key are candidate keys. I Am assuming same for (name,description,status,due_date,completed_date) in Tasks table and (Emp_id,Project_id) can not be a candidate key in any combination for this table since it is given that: "An employee will work on none or many projects An employee will be assigned to one or many tasks related to the project A task will have only one employee assigned to it".

And none of the non-prime key seems to be dependent on any other non-prime key. So there is no trasistive dependency either.

So I would say it is in 3-NF.

Sachin
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    You don't clearly justify claims based on what is given in the question. And you can't because the question doesn't give required information. If you want to make claims based on names & common sense, you don't justify that either. And since the question is so poor that is should not be answered, you haven't said anything that the asker or anyone else could apply to this or any other example. [ask] [answer] [help] – philipxy Apr 22 '20 at 06:55
  • @philipxy. Thanks for pointing that out. The question does seems too specific and vague and I did make some assumption which seemed obvious to me but are not mentioned in the question. Snice I have already answered it I will edit my answer to make it more clear. – Sachin Apr 25 '20 at 13:35
  • I appreciate the thanks. PS You really need to first say for every FD using the attributes whether it holds or not & why, then the rest is per FDs. Although a presentation & justification for "the rest" is rewriting a textbook & if not a complete presentation is just fragments of thoughts--where does the explanation stop?--the question is too broad. PS We don't normaiize via lower NFs. ["1NF" has no one meaning.](https://stackoverflow.com/a/40640962/3404097) Your 2NF & 3NF criteria are wrong. "All CKs simple implies 2NF" is [a misconception](https://stackoverflow.com/a/16617091/3404097) . – philipxy Apr 25 '20 at 22:21