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- Question
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
- Correct Answer
- ALTER TABLE TableName ADD ColumnName
- 1. 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
- 2. 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
- 3. 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. Discuss
- 4. 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
- 5. Each entity is represented as a(n):
Options- A. tuple.
- B. table.
- C. attribute.
- D. file. Discuss
- 6. 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
- 7. 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
- 8. How can you find rows that do not match some specified condition?
Options- A. EXISTS
- B. Double use of NOT EXISTS
- C. NOT EXISTS
- D. None of the above is correct. Discuss
- 9. What SQL command can be used to delete columns from a table?
Options- A. MODIFY TABLE TableName DROP COLUMN ColumnName
- B. MODIFY TABLE TableName DROP ColumnName
- C. ALTER TABLE TableName DROP COLUMN ColumnName
- D. ALTER TABLE TableName DROP ColumnName Discuss
- 10. Which of the following SQL statements are helpful in database redesign?
Options- A. Correlated subqueries only
- B. EXISTS/NOT EXISTS expressions only
- C. Both of the above are helpful
- D. None of the above are helpful. Discuss
Database Redesign problems
Search Results
Correct Answer: the child table.
Correct Answer: either table without specifying parent and child tables.
Correct Answer: NOT NULL.
Correct Answer: All of the above use ID dependent entities
Correct Answer: table.
Correct Answer: all rows in the subquery fail the condition.
Correct Answer: from the bottom up.
Correct Answer: Double use of NOT EXISTS
Correct Answer: ALTER TABLE TableName DROP COLUMN ColumnName
Correct Answer: Both of the above are helpful
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