Which of the following statements is correct? ( refer to the tables in the JustLee Books database). a. A PRIMARY KEY constraint allows NULL values in the primary key column(s). b. You can enable a dropped constraint if you need it in the future. c. Every table must have at least one PRIMARY KEY constraint, or Oracle 12 c doesn’t allow the table to be created. d. None of the above statements is correct
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Which of the following statements is correct? ( refer to the tables in the JustLee Books
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