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Rolling Back from Transactions
1:15Sometimes errors happen in the middle of a transaction. How do you recover from that? This video shows you how!
Now that you've seen the benefit of using
transactions in database save files,
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you may be tempted to use them on your
own for a series of complex updates.
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Now, what happens in the middle of
a transaction when you make a typo or
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you forget something, and
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you just want to get rid of the changes
that haven't been committed yet?
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This is where the rollback
statement comes in.
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Let's say you begin your transaction and
start inserting rows.
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You can even select to see them added,
but they're not really added.
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No one else can see them
if they run the same query.
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It's just for you to review.
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[SOUND] Then you realize you've done
a typo in all of your statements and
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you feel like starting over.
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That's where rollback comes in.
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To undo it,
we issue the rollback statement.
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When you select from the table now,
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the entries you tried to
insert aren't there anymore.
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That's because they weren't
there in the first place.
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You didn't commit your changes.
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You may have issued multiple
code operations in one go.
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And issuing them by hand
can be problematic.
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But rolling back is always an option.
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