[GENERAL] Is it possible to have multiple names for a column?
We have a need to rename some columns, but since we can't update both the database and the programs instantly, we'd like to temporarily assign both names to the same column while the updates are in progress. Something like this would be super nifty :-) ALTER TABLE howdy_doody ADD NAME xyzzy TO COLUMN plugh; I am pretty certain no such SQL command exists. But is it possible to do something sneaky to the internal tables so that two names point to the same columnand everything just works? Everything meaning updates, inserts, etc, not further ALTER TABLE and so on. -- ... _._. ._ ._. . _._. ._. ___ .__ ._. . .__. ._ .. ._. Felix Finch: scarecrow repairman rocket surgeon / [EMAIL PROTECTED] GPG = E987 4493 C860 246C 3B1E 6477 7838 76E9 182E 8151 ITAR license #4933 I've found a solution to Fermat's Last Theorem but I see I've run out of room o ---(end of broadcast)--- TIP 4: Have you searched our list archives? http://archives.postgresql.org
Re: [GENERAL] Is it possible to have multiple names for a column?
[EMAIL PROTECTED] writes: I am pretty certain no such SQL command exists. But is it possible to do something sneaky to the internal tables so that two names point to the same columnand everything just works? No ... at least not for usefully large values of work. You might be able to do something involving a view that renames the column in question, with as-yet-unconverted clients made to reference the view. Offhand I'm not convinced that's easier than just fixing the clients though ... regards, tom lane ---(end of broadcast)--- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
Re: [GENERAL] Is it possible to have multiple names for a column?
On Thu, 2006-09-14 at 14:18, [EMAIL PROTECTED] wrote: We have a need to rename some columns, but since we can't update both the database and the programs instantly, we'd like to temporarily assign both names to the same column while the updates are in progress. Something like this would be super nifty :-) ALTER TABLE howdy_doody ADD NAME xyzzy TO COLUMN plugh; I am pretty certain no such SQL command exists. But is it possible to do something sneaky to the internal tables so that two names point to the same columnand everything just works? Everything meaning updates, inserts, etc, not further ALTER TABLE and so on. You could create a view, make the two outside names reference the one inside name, and create a trigger to update based on which one if given data and throw an error if you try to update both columns at the same time. Sounds like a lot of work though. ---(end of broadcast)--- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
Re: [GENERAL] Is it possible to have multiple names for a column?
On Thu, Sep 14, 2006 at 12:18:05PM -0700, [EMAIL PROTECTED] wrote: We have a need to rename some columns, but since we can't update both the database and the programs instantly, we'd like to temporarily assign both names to the same column while the updates are in progress. Something like this would be super nifty :-) ALTER TABLE howdy_doody ADD NAME xyzzy TO COLUMN plugh; If the clients only read the column, you could just add the new column and create triggers that copy the value from the other column on any modification. Later you drop the old column and the triggers. Maybe an approch based on rules might work? Dunno, haven't used them yet. regards, bkw ---(end of broadcast)--- TIP 5: don't forget to increase your free space map settings
