Why we haven't boolean datatype in Firebird?

Question

Unless I'm totally wrong, we have no boolean datatype (1 bit) in Firebird, even SQL Server. Why? I think boolean usefull in various situations... And very low space consuption...

Answer 1

Firebird 3 introduces the boolean datatype. See the Firebird 3 release notes, BOOLEAN data type. You can get Firebird 3 from http://www.firebirdsql.org/en/firebird-3-0/

See also the original announcement: http://asfernandes.blogspot.com/2010/12/introducing-boolean-datatype.html

Answer 2

you have to create domain for it

CREATE DOMAIN D_BOOLEAN
 AS smallint
 CHECK (VALUE IS NULL OR VALUE IN (0, 1));

and then

alter table sometable add somefield d_boolean

works perfectly at our DB :)