Which of the Following Constraints Cannot Be Added to an Existing

question 94

Multiple Choice

Which of the following constraints cannot be added to an existing table with the ADD clause of the ALTER TABLE command?​

• A) ​CHECK
• B) ​UNIQUE
• C) ​NOT NULL
• D) ​none of the above

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Definitions:

DSM

The Diagnostic and Statistical Manual of Mental Disorders, a standard classification of mental disorders used by mental health professionals.

Axis I Disorder

A classification used in previous versions of the DSM, referring primarily to mental disorders that are acute and typically symptomatic, such as mood disorders and anxiety disorders.

DSM-IV-TR

The Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision; a manual published by the American Psychiatric Association that includes all currently recognized mental health disorders.

Personality Disorders

A group of mental disorders characterized by enduring maladaptive patterns of behavior, cognition, and inner experience, exhibited across many contexts and deviating from cultural norms.