alleryStart learning →Which constraint ensures a column cannot hold missing or unknown values?
ANOT NEEDED
BNOT NULL
CNOT NAMED
DNOT NESTED
Answer & Solution
Correct answer: B. NOT NULL
1. NULL stands for a missing or unknown value.
2. One constraint forbids it in a column.
3. NOT NULL ensures that a column cannot have NULL values.
4. So the answer is NOT NULL.
_Source: syllabus Computer Science, Ch 9 'Structured Query Language (SQL)'_
Keep practising Structured Query Language
Browse all Structured Query Language questions for IGNOU MCA, or explore more Computer Science topics.