What is the correct result after executing the entire script below from top to bottom?

Question

BlackTom AI · Accepted Answer

Let’s walk through the statements by following the script’s flow step by step to see which changes persist at the end.

Option A: All updates are undone, and the phone numbers for all four customers remain unchanged.
- This would be true only if a full rollback occurred after the last operation. However, the script performs a rollback specifically to savepoint three, not to the initial state. Since updates up to savepoint three are preserved, this option incorrectly suggests no updates persist.

Option B: The phone number for customer 2001 is updated, while those for customers 2007, 2010, and 2013 remain unchanged (undone).
- The first update to 2001 happens before savepoint one. A later commit at savepoint two preserves the 2001 change. The subsequent updates to 2007 and 2010 are also performed before the rollback to savepoint three, so they survive the rollback. Therefore, this option incorrectly states that 2007 and 2010 were undone.

Option C: The phone numbers for customers 2001 and 2007 are updated, while those for customers 2010 and 2013 remain unchanged (undone).
- This option would hold if the rollback happened after the 2010 update but before the 2007 update, or if the 2007 update had been undone by some later operation. However, the script commits after updating 2007, so that change is preserved. Thus, this option incorrectly claims 2007 was undone and 2010 also remained unchanged.

Option D: The phone numbers for customers 2001, 2007, and 2010 are updated, but the account for customer 2013 remains unchanged.
- This aligns with the sequence: update 2001 (savepoint one), then update 2007 (commit and savepoint two), then update 2010 (savepoint three). The final update to 2013 occurs after savepoint three, but the rollback to savepoint three undoes only changes made after that point, so the 2013 update is rolled back. Consequently, 2001, 2007, and 2010 remain updated, while 2013 remains unchanged. This is the correct outcome according to the described rollback behavior.

In summary, each option was assessed against the exact order of operations and the effect of the rollback to savepoint three. The persistent changes are those made up to and including the savepoint three, while the last update (to 2013) is undone by the rollback.

What is the correct result after executing the entire script below from top to bottom?单项选择题

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