Question

A __________ value is specified for the column, if no value is provided.

• A. unique
• B. null
• C. default
• D. primary

Hint:

Always use DEFAULT for automatic values (e.g., DEFAULT 0 or DEFAULT 'Unknown') when no value is supplied.

Answer 1

The Correct Option is C

Step 1: Recall concept of default value.
In SQL, when creating a table, a column can be given a DEFAULT value. If no explicit value is inserted, the column automatically takes the default value.
Step 2: Evaluate options.
- Unique: Constraint ensures all values in a column are distinct, not a fallback value.
- Null: Absence of value, not automatically assigned unless allowed.
- Default: A predefined value inserted when no value is given.
- Primary: Refers to primary key constraint, not applicable here.
Final Answer: \[ \boxed{\text{Default value is specified if no value is provided.}} \]