Re: null foreign key column - Mailing list pgsql-sql
| From | Dmitry Tkach |
|---|---|
| Subject | Re: null foreign key column |
| Date | |
| Msg-id | b2ebqi$9eb$1@news.hub.org Whole thread Raw |
| In response to | null foreign key column ("Arunachalam Jaisankar" <jsankar@xtra.co.nz>) |
| Responses |
Re: null foreign key column
(Vernon Wu <vernonw@gatewaytech.com>)
|
| List | pgsql-sql |
You don't want it to be serial - just make it 'person_id in' I hope, it helps... Dima Arunachalam Jaisankar wrote: > This is a multi-part message in MIME format. > > ------=_NextPart_000_0005_01C2D1EE.61998D70 > Content-Type: text/plain; > charset="iso-8859-1" > Content-Transfer-Encoding: quoted-printable > > Hi all, > > I would like to have a foreign key column in my table which allows null val= > ue also. > But the below create table sql command doesn't accept null value for person= > _id. > How to do in postgres? > > create table event > ( > event_id serial not null, > event_description char(255) , > person_id serial , > primary key (event_id), > foreign key (person_id) > references person (person_id) > ); > > regards > Jai > ------=_NextPart_000_0005_01C2D1EE.61998D70 > Content-Type: text/html; > charset="iso-8859-1" > Content-Transfer-Encoding: quoted-printable > > <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> > <HTML><HEAD> > <META http-equiv=3DContent-Type content=3D"text/html; charset=3Diso-8859-1"> > <META content=3D"MSHTML 6.00.2800.1106" name=3DGENERATOR> > <STYLE></STYLE> > </HEAD> > <BODY bgColor=3D#ffffff> > <DIV><FONT face=3DArial size=3D2>Hi all,</FONT></DIV> > <DIV><FONT face=3DArial size=3D2></FONT> </DIV> > <DIV><FONT face=3DArial size=3D2>I would like to have a foreign key column = > in my=20 > table which allows null value also.</FONT></DIV> > <DIV><FONT face=3DArial size=3D2>But the below create table sql command doe= > sn't=20 > accept null value for person_id.</FONT></DIV> > <DIV><FONT face=3DArial size=3D2>How to do in postgres?</FONT></DIV> > <DIV><FONT face=3DArial size=3D2></FONT><FONT face=3DArial size=3D2></FONT>= > </DIV> > <DIV><FONT face=3DArial size=3D2>create table event<BR>(<BR> &nb= > sp;=20 > event_id &= > nbsp; =20 > serial &nb= > sp; =20 > not null,<BR> event_description &n= > bsp;=20 > char(255) = > =20 > ,<BR> =20 > person_id = > =20 > serial &nb= > sp; =20 > ,<BR> primary key (event_id),<BR> forei= > gn=20 > key (person_id)<BR> references pe= > rson=20 > (person_id)<BR>);</FONT></DIV> > <DIV><FONT face=3DArial size=3D2></FONT> </DIV> > <DIV><FONT face=3DArial size=3D2>regards</FONT></DIV> > <DIV><FONT face=3DArial size=3D2>Jai</FONT></DIV></BODY></HTML> > > ------=_NextPart_000_0005_01C2D1EE.61998D70-- >