Trying to explain 2nd/3rd normal form

Discussion in 'computers, web and general tech' started by Shippou-Sensei, Mar 16, 2017.

  1. Shippou-Sensei

    Shippou-Sensei 4:1:2.5

    Man I am struggling to try and articulate the difference between 2nd and 3rd normal form to my BTEC lvl 3 students.

    1st normal form is dead simple but while I can get the point across about attributes dependance on the primary key I'm getting stuck on the difference between 2 and 3.

    It's probably mainly because I only just sorta get it myself but man I'm just coming up short on a way to put a simple explanation together for a bunch of bored 17 year old who are doing databases because they dropped out of the programming class.

    Online resources aren't helping so far.
    Pickman's model likes this.
  2. Pickman's model

    Pickman's model every man and every woman is a star

    does this help? Database Normalization: First, Second, and Third Normal Forms - Andrew Rollins

    maybe this? Differences between 1st, 2nd and 3rd normal form | Business Intelligence Solutions Freelance Australia NSW Sydney
    a_chap likes this.
  3. Shippou-Sensei

    Shippou-Sensei 4:1:2.5

    Not quite.

    I find the process easier to do than to explain.

    Those sites help somewhat but I'm still a long way from a nice set of rules written in a simple language to give to struggling students.
    Pickman's model likes this.
  4. Pickman's model

    Pickman's model every man and every woman is a star

    SQL First, Second and Third Normal Forms - dummies ?
  5. Shippou-Sensei

    Shippou-Sensei 4:1:2.5

    Well it's helping me with my understanding so that's a plus.

    This unit is a wierd one. Doing some in depth stuff in theory but then setting criteria that force me to use access.
  6. Shippou-Sensei

    Shippou-Sensei 4:1:2.5

    Looking at the slides used by the previous lecture that just compleat ignored normalisation all together.

  7. mauvais

    mauvais change has become unavoidable

    I might be oversimplifying this as databases are not my area of expertise, but:

    2NF means you have to separate out data where its value can be inferred from part of the primary key.

    3NF means you also have to separate out data that can be inferred from any other column.

    Look at the 'green tick' answer here:

    What are 1NF, 2NF and 3NF in database design?

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