On Sun, 2004-08-29 at 15:30, Bruno Wolff III wrote: > On Fri, Aug 27, 2004 at 13:32:07 +0530, > Yateen Joshi <[EMAIL PROTECTED]> wrote: > > Hi, > > > > I have got a table which is supposed to contain only one row. It does > > not have any primary keys defined. > > So, essentially, when a new insert happens in that table, I would like > > it (the insert) to fail if there is already a row existing in that > > table. > > How can I do that? Can I add any constraints? Or do I need to write a > > separate trigger for the same? > > A simple way to force this is to add a primary key and a constraint > that forces the primary key to be a particular value.
Is it reasonable / possible to add a check constraint something like select count(*) from table <=1? ---------------------------(end of broadcast)--------------------------- TIP 9: the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match