Обсуждение: inheritance question
Hi All! That probably was already asked thousand times but i did not find an exact answer: I want to have two tables the second one will have all the columns from the first + some extra .The data should be complittly separate .I was trying to use inheritance and setted the SQL_INHERITANCE = false to separate the data ,but when trying to add a column to the father i have got an error: ERROR: Attribute must be added to child tables too what can i do ? Thanks Evgeny.
According to your posting below the second table will have all the columns of the first table plus extra columns. If that is true then why are you trying to add a column to your first table and not your second table as well? On Tue, 2004-07-13 at 06:32, evgeny tsurkin wrote: > Hi All! > That probably was already asked thousand times > but i did not find an exact answer: > I want to have two tables the second one will have > all the columns from the first + some extra .The data > should be complittly separate .I was trying to use > inheritance and setted the SQL_INHERITANCE = false > to separate the data ,but when trying to add a column > to the father i have got an error: > ERROR: Attribute must be added to child tables too > what can i do ? > Thanks > Evgeny. > > > ---------------------------(end of broadcast)--------------------------- > TIP 4: Don't 'kill -9' the postmaster
I am but that is what actually want : to be able to add a column to the first table and have the second to be added a coulumns automatically.The target is realy simple : i want to simplify management of the schema and thus be able to manage only parantes - children should be managed aoutomagically But the data is NOT the same! Isn't it the inheretence is all about - to inherit? On Fri, 16 Jul 2004, mike g wrote: > According to your posting below the second table will have all the > columns of the first table plus extra columns. If that is true then why > are you trying to add a column to your first table and not your second > table as well? > > On Tue, 2004-07-13 at 06:32, evgeny tsurkin wrote: > > Hi All! > > That probably was already asked thousand times > > but i did not find an exact answer: > > I want to have two tables the second one will have > > all the columns from the first + some extra .The data > > should be complittly separate .I was trying to use > > inheritance and setted the SQL_INHERITANCE = false > > to separate the data ,but when trying to add a column > > to the father i have got an error: > > ERROR: Attribute must be added to child tables too > > what can i do ? > > Thanks > > Evgeny. > > > > > > ---------------------------(end of broadcast)--------------------------- > > TIP 4: Don't 'kill -9' the postmaster > -- ------------------------------------------- Evgeny.
On Tue, 13 Jul 2004, evgeny tsurkin wrote: > Hi All! > That probably was already asked thousand times > but i did not find an exact answer: > I want to have two tables the second one will have > all the columns from the first + some extra .The data > should be complittly separate .I was trying to use > inheritance and setted the SQL_INHERITANCE = false > to separate the data ,but when trying to add a column > to the father i have got an error: > ERROR: Attribute must be added to child tables too > what can i do ? Either don't use SQL_INHERITANCE=false, or specify that you want to act upon the entire tree using the older syntax which I think would look like ALTER TABLE first* add column ... (note the *)
But this way i will touch both the schema AND data And what i want is to change the schema ONLY. Thanks On Sun, 18 Jul 2004, Stephan Szabo wrote: > On Tue, 13 Jul 2004, evgeny tsurkin wrote: > > > Hi All! > > That probably was already asked thousand times > > but i did not find an exact answer: > > I want to have two tables the second one will have > > all the columns from the first + some extra .The data > > should be complittly separate .I was trying to use > > inheritance and setted the SQL_INHERITANCE = false > > to separate the data ,but when trying to add a column > > to the father i have got an error: > > ERROR: Attribute must be added to child tables too > > what can i do ? > > Either don't use SQL_INHERITANCE=false, or specify that you want > to act upon the entire tree using the older syntax which I think > would look like ALTER TABLE first* add column ... > (note the *) > > > > ---------------------------(end of broadcast)--------------------------- > TIP 7: don't forget to increase your free space map settings > -- ------------------------------------------- Evgeny.
On Mon, 19 Jul 2004, Tsirkin Evgeny wrote: > But this way i will touch both the schema AND data > And what i want is to change the schema ONLY. The use the ALTER TABLE table* ADD COLUMN syntax to alter the schema for table and its descendants. In general, SQL_INHERITANCE=false is primarily there for applications that were written for older versions of PostgreSQL. You probably should be using queries that use the ONLY keyword rather than relying on the guc variable. > On Sun, 18 Jul 2004, Stephan Szabo wrote: > > > On Tue, 13 Jul 2004, evgeny tsurkin wrote: > > > > > Hi All! > > > That probably was already asked thousand times > > > but i did not find an exact answer: > > > I want to have two tables the second one will have > > > all the columns from the first + some extra .The data > > > should be complittly separate .I was trying to use > > > inheritance and setted the SQL_INHERITANCE = false > > > to separate the data ,but when trying to add a column > > > to the father i have got an error: > > > ERROR: Attribute must be added to child tables too > > > what can i do ? > > > > Either don't use SQL_INHERITANCE=false, or specify that you want > > to act upon the entire tree using the older syntax which I think > > would look like ALTER TABLE first* add column ... > > (note the *)