Oracle Database SQL — Question 159

Which two statements are true about an Oracle database? (Choose two.)

Answer options

• A. A table can have multiple primary keys.
• B. A column definition can specify multiple data types.
• C. A table can have multiple foreign keys.
• D. A VARCHAR2 column without data has a NULL value.
• E. A NUMBER column without data has a zero value.

Correct answer: C, D

Explanation

Option C is correct because a table can indeed have multiple foreign keys that reference different primary keys in other tables. Option D is also correct, as a VARCHAR2 column without any data will store a NULL value. Options A and B are incorrect because a table can only have one primary key and a column can only have a single data type. Option E is incorrect since a NUMBER column without data will also have a NULL value, not zero.