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Home Database Data Models into Database Designs Comments

  • Question
  • A primary key should be defined as:


  • Options
  • A. NULL.
  • B. NOT NULL.
  • C. Either of the above can be used.
  • D. None of the above are correct.

  • Correct Answer
  • NOT NULL. 


  • Data Models into Database Designs problems


    Search Results


    • 1. Which of the following situation requires the use of ID-dependent entities?

    • Options
    • A. Association relationships only
    • B. Multivalued attributes only
    • C. Archetype/instance relationships only
    • D. All of the above use ID dependent entities
    • Discuss
    • 2. Each entity is represented as a(n):

    • Options
    • A. tuple.
    • B. table.
    • C. attribute.
    • D. file.
    • Discuss
    • 3. The identifier of an entity will become the ________ of the new table.

    • Options
    • A. foreign key
    • B. main attribute
    • C. primary key
    • D. identity key
    • Discuss
    • 4. Which of the following column properties would be used to specify that cells in a column must be immediately filled with a monetary value of $10,000?

    • Options
    • A. Null status
    • B. Data type
    • C. Default value
    • D. Data constraints
    • Discuss
    • 5. Which of the following data constraints would be used to specify that the value of a cell in one column must be less than the value of a cell in another column in the same row of the same table?

    • Options
    • A. A domain constraint
    • B. A range constraint
    • C. An intrarelation constraint
    • D. An interrelation constraint
    • Discuss
    • 6. In a 1:1 relationship, the foreign key is placed in:

    • Options
    • A. either table without specifying parent and child tables.
    • B. the parent table.
    • C. the child table.
    • D. either the parent table or the child table.
    • Discuss
    • 7. In a 1:N relationship, the foreign key is placed in:

    • Options
    • A. either table without specifying parent and child tables.
    • B. the parent table.
    • C. the child table.
    • D. either the parent table or the child table.
    • Discuss
    • 8. What SQL command can be used to add columns to a table?

    • Options
    • A. MODIFY TABLE TableName ADD COLUMN ColumnName
    • B. MODIFY TABLE TableName ADD ColumnName
    • C. ALTER TABLE TableName ADD COLUMN ColumnName
    • D. ALTER TABLE TableName ADD ColumnName
    • Discuss
    • 9. The NOT EXISTS keyword will be true if:

    • Options
    • A. any row in the subquery meets the condition.
    • B. all rows in the subquery fail the condition.
    • C. both of these two conditions are met.
    • D. neither of these two conditions is met.
    • Discuss
    • 10. A regular subquery can be processed:

    • Options
    • A. from the top down.
    • B. from the bottom up.
    • C. by nesting.
    • D. None of the above is correct.
    • Discuss


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