Re: Converting between varchar and float when updating

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От Szymon Guz
Тема Re: Converting between varchar and float when updating
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Msg-id BANLkTikHTQnDTfmnaqeRyCTxJcweTi5_xw@mail.gmail.com
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Ответ на Converting between varchar and float when updating  (Thomas Larsen Wessel <mrvelle@gmail.com>)
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On 28 April 2011 11:26, Thomas Larsen Wessel <mrvelle@gmail.com> wrote:
I have a table with the following schema:
CREATE TABLE foo (bar VARCHAR(32));

Every bar value has a format like a float, e.g. "2.5". Now I want that value multiplied by two and saved again as varchar. I was hoping to do smth like:

UPDATE foo SET bar = TO_VARCHAR( TO_FLOAT(bar) * 2); -- INCORRECT!!!!

How is that done?

I know that the bar attribute ought to have type FLOAT, but I have to work with this legacy database. And anyway this table will rarely be updated.

Sincerely, Thomas


Hi,
maybe try this instead:

UPDATE foo SET bar = (bar::float * 2) :: text;

regards
Szymon

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