Database-MySQL [3i Infotech Placement]: Sample Questions 56 - 57 of 162

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Question 56

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Describe in Detail

Essay▾

What is 2NF?

Explanation

  • A relation schema R is in 2NF if it is in 1NF and every non-prime attribute A in R is fully functionally dependent on primary key.

    2NF (Second Normal Form) Rules

  • It is clear that we can՚t move forward to make our simple database in 2nd Normalization form unless we partition the table above.
Second Normal Form Rules in Table
MEMBERSHIP IDFULL NAMESPHYSICAL ADDRESSSALTUTATION
1JanatFirst street Plot No 4Ms.
2Rohit3rd street 34Mr.
3Rohit5th AvenueMr.
Second Normal Form Rules in Table
MEMBERSHIP IDMOVIES RENTED
1Pirates of the Caribbean
1Clash of the Titans
2Forgetting sarah Marshal
2Daddy՚s Little Girls
3Clash of the Titans
  • We have divided our 1NF table into two tables viz. Table 1 and Table2.
  • Table 1 contains member information. Table 2 contains information on movies rented.
  • We have introduced a new column called Membership_id which is the primary key for table 1. Records can be uniquely identified in Table 1 using membership id

Question 57

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Write in Short

Short Answer▾

Give some examples of Analytical functions.

Explanation

Analytical functions examples is AVG, LEAD, and PERCENTILE_RANK.

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