Multiple choice

Which of the following is the correct way of defining the CHECK constraint?

  1. CREATE TABLE STUDENTS( STUDENT_ID INT NOT NULL, STUDENT_NAME VARCHAR (20) NOT NULL, AGE INT NOT NULL CHECK (AGE >= 18), ADDRESS CHAR (25) , MARKS INT, PRIMARY KEY (STUDENT_ID));

  2. CREATE TABLE STUDENTS( STUDENT_ID INT NOT NULL, STUDENT_NAME VARCHAR (20) NOT NULL, AGE INT NOT NULL , ADDRESS CHAR (25) , MARKS INT, PRIMARY KEY (STUDENT_ID)); ALTER TABLE STUDENTS MODIFY AGE INT NOT NULL CHECK (AGE >= 18 );

  3. CREATE TABLE STUDENTS( STUDENT_ID INT NOT NULL, STUDENT_NAME VARCHAR (20) NOT NULL, AGE INT NOT NULL , ADDRESS CHAR (25) , MARKS INT, PRIMARY KEY (STUDENT_ID));ALTER TABLE STUDENTS ADD CONSTRAINT myCheckConstraint CHECK(AGE >= 18);

  4. Check constraint has introduced only from ORACLE 10g onwards.

  5. All Option 1, Option 2 and Option 3 are correct.
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Yes, All three options are correct.

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