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Removing Data from All Rows in a Table
1:27In this video, we'll see how to delete all data from a table.
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Remember the four CRUD operations,
create, read, update, and delete.
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We know the first three keywords too.
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Insert to create, select to read,
and update to update.
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Just like update, delete's keyword
is the same as the action.
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Delete.
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To write a delete statement,
you'd write something like this.
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DELETE FROM table name.
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The delete keyword removes
rows from a table.
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It doesn't just empty the rows' values,
it removes the rows altogether.
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Let's delete all the data from a table.
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Let’s imagine we’ve had the sad news
that our library was closing down.
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We’ve sold all the books in our library,
and
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we need to get rid of all
the personal data in our library.
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Let’s use the DELETE FROM statement to
remove all data from the books table.
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When we view the books table now,
there are no rows remaining.
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Now how about wiping out
all of the sensitive
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information from the patrons table?
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We can just modify the delete from
book state to say delete from patrons.
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Simple.
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When we execute this now, all of
the patron information has been removed.
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It's important to note,
you can't undo this.
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Without a backup of your data,
you can't restore it.
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