Re: change existing table definition

Hi,

Thanks a lot for your quick reply and help. The following is what I find
from google.  Will it work?

A quicker solution would be to use the pg_dump command
to dump the table, change the needed columns and restore
everything.

pg_dump -c -t <table name> <database> > <dumpfile>
psql <database> < <dumpfile>


Regards,

Chuming


Martin Fandel wrote:

>Aehm sorry. ALTER TABLE is not only in PostgreSQL 8 ;). Only the
>datatypes can be changed in postgres 8 (right?). I answered to fast.
>I'm sorry.
>
>CREATE TABLE newtable ( "bla" varchar(50));
>CREATE INDEX/TRIGGER/... (with different names as the production table)
>INSERT INTO newtable (select * from production);
>ALTER TABLE production RENAME TO old;
>ALTER TABLE newtable RENAME TO production;
>
>If this is working correctly, you can drop the old INDEXES and
>rename them.
>
>If its not working correctly
>
>ALTER TABLE production RENAME TO new;
>ALTER TABLE old RENAME TO production;
>
>and insert the different data (which is in the oldtable) into the
>production table.
>
>Greetings,
>Martin
>
>
>Am Dienstag, den 28.06.2005, 17:29 +0200 schrieb Martin Fandel:
>
>
>>Hi
>>
>>ALTER TABLE is only in PostgreSQL 8. But you can create a new table
>>with varchar(50) and copy the data from the existing into the new
>>table. How much relation_size has your table? Do you create the
>>dbsize-functions which are included in the contrib package?
>>
>>Best regards,
>>Martin
>>
>>Am Dienstag, den 28.06.2005, 10:39 -0400 schrieb Chuming Chen:
>>
>>
>>>Peter Eisentraut wrote:
>>>
>>>
>>>
>>>>Chuming Chen wrote:
>>>>
>>>>
>>>>
>>>>
>>>>>How can I change the column definition of an existing table, ie. from
>>>>>varchar(30) to varchar(50)? Is there any way to add a new column to
>>>>>an existing table?
>>>>>
>>>>>
>>>>>
>>>>>
>>>>The ALTER TABLE command can do all that.  You need version 8.0 or later
>>>>for some functionality though.
>>>>
>>>>
>>>>
>>>>
>>>>
>>>Is there another way to do it in 7.* ?
>>>
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>>>
>
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