How can you modify the users table to ensure the email column cannot be NULL and has a default value of 'unknown@example.com'?

hard📝 Application Q9 of 15

SQL - Table Constraints

How can you modify the users table to ensure the email column cannot be NULL and has a default value of 'unknown@example.com'?

AALTER TABLE users SET email NOT NULL DEFAULT 'unknown@example.com';

BALTER TABLE users ADD CONSTRAINT email NOT NULL DEFAULT 'unknown@example.com';

CALTER TABLE users CHANGE email NOT NULL DEFAULT 'unknown@example.com';

DALTER TABLE users MODIFY email VARCHAR(100) NOT NULL DEFAULT 'unknown@example.com';

Step-by-Step Solution

Solution:

Step 1: Understand how to modify column constraints and defaults
You must use MODIFY with the data type, NOT NULL, and DEFAULT value.
Step 2: Check syntax correctness
ALTER TABLE users MODIFY email VARCHAR(100) NOT NULL DEFAULT 'unknown@example.com'; correctly uses ALTER TABLE ... MODIFY column datatype NOT NULL DEFAULT value.
Final Answer:
ALTER TABLE users MODIFY email VARCHAR(100) NOT NULL DEFAULT 'unknown@example.com'; -> Option D
Quick Check:
Use MODIFY with NOT NULL and DEFAULT to change column [OK]

Quick Trick: Use MODIFY with datatype, NOT NULL, and DEFAULT [OK]

Common Mistakes:

MISTAKES

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