On Wed, 18 Jan 2012 23:08:36 +0100, "Ivan Prenosil" <ivan.preno...@seznam.cz> wrote: >> I have a table: >> recreate table test ( >> base numeric(15,4), >> test1 computed by (base+base), >> test2 computed by (cast(base+base as numeric(15,4))), >> foo bigint, >> bar numeric(15,4) >> ); >> >> If I run the query: >> select rf.RDB$FIELD_NAME, f.RDB$FIELD_SCALE, f.RDB$FIELD_TYPE, >> f.RDB$FIELD_SUB_TYPE >> from RDB$RELATION_FIELDS rf inner join RDB$FIELDS f on >> (rf.RDB$FIELD_SOURCE = f.RDB$FIELD_NAME) >> where rf.RDB$RELATION_NAME = 'TEST' >> it reports: >> BASE -4 16 1 >> TEST1 -4 16 0 >> TEST2 -4 16 1 >> FOO 0 16 0 >> BAR -4 16 1 >> >> Why is rdb$field_sub_type for test1 column "0"? Then it looks like >> bigint. Checking the rdb$field_scale could be a solution, but is it >> then numeric or decimal? > > I would say it is expected. Numeric expressions generally do not preserve > data types exactly. E.g. > SmallintField + 1 -> result is Bigint > NumericField(9, 2) + 1 -> result is .. ehm ... Num/Dec(18, 2) (API will > return zero as subtype)
I think it shouldn't, if something is defined as a DECIMAL or NUMERIC it should specify subtype 2 or 1, never 0. And if it has subtype 0 it should not be allowed to have a scale other than 0. > Or consider this - what (sub)type do you think should return this > expression ? > NumericField(15, 4) + DecimalField(15, 4) I would expect DECIMAL(15,4) or maybe DECIMAL(16,4) to allow for overflow as according to the SQL spec NUMERIC has a precision of exactly the specified number, while DECIMAL has a precision of the specified number or higher. Mark ------------------------------------------------------------------------------ Keep Your Developer Skills Current with LearnDevNow! The most comprehensive online learning library for Microsoft developers is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3, Metro Style Apps, more. Free future releases when you subscribe now! http://p.sf.net/sfu/learndevnow-d2d Firebird-Devel mailing list, web interface at https://lists.sourceforge.net/lists/listinfo/firebird-devel
