ALTER TABLE inventory ENABLE CONSTRAINT inventory_id_pk; Which statement is true?
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The statement will achieve the desired results
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The statement will execute, but will NOT enable the PRIMARY KEY constraint.
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The statement will execute, but will NOT verify that values in the ID column do NOT violate the constraint.
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The statement will return a syntax error.
The ALTER TABLE...ENABLE CONSTRAINT command re-enables a previously disabled constraint. This will successfully enable the PRIMARY KEY constraint inventory_id_pk and validate existing data, achieving the desired result.
To determine which statement is true, let's go through each option:
Option A) The statement will achieve the desired results - This option is correct because the statement is using the "ENABLE CONSTRAINT" command to enable the PRIMARY KEY constraint on the "inventory_id_pk" constraint. By executing this statement, the PRIMARY KEY constraint will be enabled and enforced on the "ID" column of the "inventory" table.
Option B) The statement will execute, but will NOT enable the PRIMARY KEY constraint - This option is incorrect. The statement will enable the PRIMARY KEY constraint as specified.
Option C) The statement will execute, but will NOT verify that values in the ID column do NOT violate the constraint - This option is incorrect. When the PRIMARY KEY constraint is enabled, it will verify that values in the "ID" column do not violate the constraint (i.e., there are no duplicate values or NULL values).
Option D) The statement will return a syntax error - This option is incorrect. The syntax of the statement is correct, so it will not return a syntax error.
Therefore, the correct answer is Option A) The statement will achieve the desired results.