Thread: Inherancing
Hi people, supposing i have the tables : create table cities (id int, name varchar, primary key(id) ); create table centers (state varchar(2)) inherits (cities); ant the tuple insert into cities values (1, 'Lajeado'); How i do if i want to make this city as a center ? Thanks, xx===============================xx || °v° Nasair Junior da Silva || || /(_)\ Linux User: 246054 || || ^ ^ njunior@univates.br || ||CPD - Desenvolvimento || ||Univates - Centro Universitário|| xx===============================xx
On 7/1/03 11:42 am, "Nasair Junior da Silva" <njunior@univates.br> wrote: > Hi people, > supposing i have the tables : > > create table cities (id int, name varchar, primary key(id) ); > create table centers (state varchar(2)) inherits (cities); > > ant the tuple > insert into cities values (1, 'Lajeado'); > > How i do if i want to make this city as a center ? If I understand you correctly you probably want to do this instead... insert into centers values (1, 'Lajeado', 'AZ'); Where AZ is your state HTH adam -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean.
In this case, when i do select * from cities; i'll have two tuples with the name 'Lajeado'. Does it the only way i have ? Thanks again, Nasair Júnior da Silva Lajeado - RS - Brasil. Em Tue, 07 Jan 2003 12:02:13 +0000, Adam Witney <awitney@sghms.ac.uk> escreveu: >On 7/1/03 11:42 am, "Nasair Junior da Silva" <njunior@univates.br> wrote: > >> Hi people, >> supposing i have the tables : >> >> create table cities (id int, name varchar, primary key(id) ); >> create table centers (state varchar(2)) inherits (cities); >> >> ant the tuple >> insert into cities values (1, 'Lajeado'); >> >> How i do if i want to make this city as a center ? > >If I understand you correctly you probably want to do this instead... > >insert into centers values (1, 'Lajeado', 'AZ'); > >Where AZ is your state > >HTH > >adam > > xx===============================xx || °v° Nasair Junior da Silva || || /(_)\ Linux User: 246054 || || ^ ^ njunior@univates.br || ||CPD - Desenvolvimento || ||Univates - Centro Universitário|| xx===============================xx
Yes, if you do insert into cities values (1, 'Lajeado'); insert into centers values (1, 'Lajeado', 'AZ'); Then select * from cities will give you 1 Lajedo 1 Lajedo And select * from centers will give 1 Lajedo AZ However, if rather than duplicating the insert and just doing insert into centers values (1, 'Lajeado', 'AZ'); Then select * from cities will give you 1 Lajedo And select * from centers will give 1 Lajedo AZ Is this what you want? adam > In this case, when i do > select * from cities; > i'll have two tuples with the name 'Lajeado'. > > Does it the only way i have ? > > Thanks again, > > Nasair Júnior da Silva > Lajeado - RS - Brasil. > > Em Tue, 07 Jan 2003 12:02:13 +0000, Adam Witney <awitney@sghms.ac.uk> > escreveu: >> On 7/1/03 11:42 am, "Nasair Junior da Silva" <njunior@univates.br> wrote: >> >>> Hi people, >>> supposing i have the tables : >>> >>> create table cities (id int, name varchar, primary key(id) ); >>> create table centers (state varchar(2)) inherits (cities); >>> >>> ant the tuple >>> insert into cities values (1, 'Lajeado'); >>> >>> How i do if i want to make this city as a center ? >> >> If I understand you correctly you probably want to do this instead... >> >> insert into centers values (1, 'Lajeado', 'AZ'); >> >> Where AZ is your state >> >> HTH >> >> adam >> >> > > > xx===============================xx > || °v° Nasair Junior da Silva || > || /(_)\ Linux User: 246054 || > || ^ ^ njunior@univates.br || > ||CPD - Desenvolvimento || > ||Univates - Centro Universitário|| > xx===============================xx > > ---------------------------(end of broadcast)--------------------------- > TIP 2: you can get off all lists at once with the unregister command > (send "unregister YourEmailAddressHere" to majordomo@postgresql.org) -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean.
You have to insert in th centers-table. Because it is inherited from cities, the record is automatically in cities. Search for SELECT * FROM ONLY in the docs too. > create table cities (id int, name varchar, primary key(id) ); > create table centers (state varchar(2)) inherits (cities); > > ant the tuple > insert into cities values (1, 'Lajeado'); Lajeado isn't a center here. You should do : insert into centers .... You can do then SELECT * FROM cities -> you will get all cities. Or SELECT * FROM centers -> you will get all centers. Or SELECT * FROM ONLY cities -> you will get only cities who aren't centers. Daniel. "Nasair Junior da Silva" <njunior@univates.br> schrieb im Newsbeitrag news:20030107094225.0345a050.njunior@univates.br... > Hi people, > supposing i have the tables : > > create table cities (id int, name varchar, primary key(id) ); > create table centers (state varchar(2)) inherits (cities); > > ant the tuple > insert into cities values (1, 'Lajeado'); > > How i do if i want to make this city as a center ? > > Thanks, > > xx===============================xx > || �v� Nasair Junior da Silva || > || /(_)\ Linux User: 246054 || > || ^ ^ njunior@univates.br || > ||CPD - Desenvolvimento || > ||Univates - Centro Universit�rio|| > xx===============================xx > > ---------------------------(end of broadcast)--------------------------- > TIP 6: Have you searched our list archives? > > http://archives.postgresql.org