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Which of the following is not a basic requirement of a relational database?

A. Every column in a row must be single valued.
B. Primary keys cannot be null.
C. Foreign keys must have values that correspond to the value of another foreign key in another table.
D. All nonkey attributes in a table should describe a characteristic about the object identified by the primary key.
E. All of the above are basic requirements of a relational database.

User Smichak
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Final answer:

The correct answer is E. All of the above are basic requirements of a relational database.

The correct statement that is not a basic requirement of a relational database is C, as foreign keys must correspond to primary keys, not other foreign keys, in relational databases.

Step-by-step explanation:

The statement 'Foreign keys must have values that correspond to the value of another foreign key in another table' is not a basic requirement of a relational database. The correct requirement is that foreign keys must correspond to the value of a primary key in another table, not another foreign key.

Therefore, the correct answer to the question, 'Which of the following is not a basic requirement of a relational database?' is C. Foreign keys must have values that correspond to the value of another foreign key in another table.

Answer A, B, and D describes fundamental rules that apply to the relational database model:

  • Answer A. Every column in a row must be single valued (atomicity).
  • Answer B. Primary keys cannot be null (uniqueness and not null constraint).
  • Answer D. All nonkey attributes in a table should describe a characteristic about the object identified by the primary key (entity integrity).

In a relational database, every column in a row must be single valued, meaning that each attribute in a table must have only one value for each record. Primary keys cannot be null, as they are used to uniquely identify each record in a table. Foreign keys must have values that correspond to the value of another foreign key in another table, ensuring data integrity and consistency.

All nonkey attributes in a table should describe a characteristic about the object identified by the primary key, ensuring that the data stored in the table is relevant and meaningful.

User Gfaceless
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