Could you express:

select count(*) from mytable where intvalue = new.intvalue into :i;
if (i > 3) then
exception too_many_values;

...as a declarative constraint? If so this would be really useful to
me!

John

--- In firebird-support@yahoogroups.com, "Ann W. Harrison"
<aharrison@i...> wrote:

> What constraints can you not express in declarative language? As a
> general rule, declarative constraints allow the engine more

latitude

> to choose the optimal execution method than procedural constraints.