Re: Normalising an existing table - how?

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От Phil Endecott
Тема Re: Normalising an existing table - how?
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Msg-id 7184150@chezphil.org
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Ответ на Normalising an existing table - how?  (Graham Leggett <minfrin@sharp.fm>)
Ответы Re: Normalising an existing table - how?
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Graham Leggett wrote:
> I have an existing table containing a column in it containing
> a money value. I would like to normalise this column into a
> separate table, as the money value is to be expanded to contain
> a tax value, etc.
> 
> I have been trying to find a SQL query that will do the
> following:
> 
> - Select the money column from the table
> - Populate the new normalised table with each row containing
>   the value from the original money column
> - Write the primary keys of the new rows in the normalised
>   table, back to a new column in the original table added for
>   this purpose.

Change the order.  Do the third step first:

alter table T add column X integer;
update T set X = nextval(somesequence);

Now do the first and second steps together:

select X, MoneyColumn from T into NewTable;

Is this the sort of thing you need?

--Phil.



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