On Sun, Jan 8, 2012 at 10:12 AM, Francisco Figueiredo Jr. <francisco@xxxxxxxxxx> wrote: > On Sun, Jan 8, 2012 at 06:54, Mike Christensen <mike@xxxxxxxxxxxxx> wrote: >>>>>>> According to the manuals, Postgres has smallint (2 byte), integer (4 >>>>>>> bytes) and bigint (8 bytes).. I use a lot of structures with "bytes" >>>>>>> in my code and it's kinda annoying to cast DB output from Int16 to >>>>>>> Byte every time, especially since there's no explicit cast in .NET and >>>>>>> you have to use System.Convert(). >>>>>>> >>>>>>> Is there a work-around, or do people just cast or use Int16 in their >>>>>>> data structures? Just wondering.. I know on modern computers it >>>>>>> probably doesn't make any difference anyway.. >>>>>> >>>>>> >>>>>> Is this just about programmer convenience or is it about space efficiency >>>>>> in >>>>>> the database? BYTEA might help you. Or try declaring a DOMAIN over >>>>>> SMALLINT that limits allowed values to the range of a byte. -- Darren >>>>>> Duncan >>>>> >>>>> >>>>> This is purely programmer convenience. >>>>> >>>>> Basically, I want Npgsql to marshal the value as a .NET Byte type, if >>>>> I can find a way to do that I'm happy. Perhaps it's more of a Npgsql >>>>> question, though I'm curious as to why Postgres doesn't have an >>>>> intrinsic tinyint or byte type. >>>> >>>> >>>> Maybe Postgres doesn't need a Byte type predefined because it gives you the >>>> means to define the type yourself, such as using DOMAIN. >>>> >>>> Generally speaking, I believe it is more important for a type system to >>>> provide the means for arbitrary user-defined types which can be used in all >>>> the places as built-in-defined types, than to have large numbers of >>>> built-in-defined types. >>> >>> Precisely. postgresql's extensable nature allows you to build your >>> own types as well. If it's popular enough it'll make it into contrib, >>> then maybe core. My guess is that there's some non-trivial cost to >>> maintaining each core type, and since a byte type isn't required by >>> the SQL spec, it would take some effort to get a standard one included >>> in the core. >> >> That makes sense. >> >> I guess my question is more of a NpgSql question then. Is there a way >> to create a custom PG type, and have npgsql serialize that type in a >> dataset to a .NET Byte type? >> >> I'd probably be better off posting on the npgsql mailing list, but >> perhaps someone here knows as well.. >> > > > Hi! > > Npgsql already has support to map .Net byte data type to int2 and vice-versa. > > You can see all the supported type mappings in this file: > http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/npgsql/Npgsql2/src/NpgsqlTypes/NpgsqlTypesHelper.cs?rev=1.41&content-type=text/x-cvsweb-markup > > Check method PrepareDefaultTypesMap(). > > I hope it helps. Thanks! I'll have to mess around with this a bit more.. From what I've seen so far, functions that have int2 out parameters will return Int16 through the DataReader.. Maybe I'm doing something wrong.. Mike -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
