Multiple choice technology databases

Constraints are defined at which level

  1. row, column

  2. row, table

  3. column, table

  4. all of above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Database constraints can be defined at two levels: column level (specified inline with column definition like 'name VARCHAR2(50) NOT NULL') and table level (specified separately like 'CONSTRAINT pk_emp PRIMARY KEY (emp_id)'). Primary keys and foreign keys often require table-level definition when they involve multiple columns.

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