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What MySQL property is used to create a surrogate key in MySQL?

 

  • A.UNIQUE
  • B.SEQUENCE
  • C.AUTO_INCREMENT
  • D.None of the above -- Surrogate keys are not implemented in MySQL.

Answer: C

Correct answer: AUTO_INCREMENT

Declaring an integer column AUTO_INCREMENT makes MySQL assign the next value on each insert, which is the standard way of creating a surrogate key. Oracle of the same era had no such property and needed a sequence with a trigger instead - a difference worth remembering when porting a schema.

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