Thread: ecpg & host variables
hi- i'm looking to convert a pro*c application to something postgresql-based. i've just started to experiment with ecpg, and have been pleasantly surprised that large parts of out existing code will be useable without too much alteration. the problems that i've run into all involve variable declarations. we have a large number of complex structures that map in-house datatypes. with oracle, we could do something like this: -------------------------------------------------------- typedef struct { int id; char name[30]; char dsc[1000]; } rec_t; rec_t r; EXEC SQL SELECT id, name, dsc INTO :r.id, :r.name, :r.dsc FROM table WHERE id = :r.id; -------------------------------------------------------- to make this code work with ecpg, i've made the following changes: -------------------------------------------------------- EXEC SQL BEGIN DECLARE SECTION; typedef struct { int id; char name[30]; char dsc[1000]; } rec_t; rec_t r; EXEC SQL END DECLARE SECTION; -------------------------------------------------------- which yields the following error from ecpg: postgres.pgc:15: ERROR: invalid datatype 'typedef' is there are facility that i might be missing that would allow me to use our existing structures as host variables w/ postgres embedded sql? or am i better off just skipping ecpg and coding directly with libpq? thanks in advance for any insight you can offer. dan
Daniel Kelley <dkelley@otec.com> writes: > ... which yields the following error from ecpg: > postgres.pgc:15: ERROR: invalid datatype 'typedef' I believe ecpg was just recently fixed to support typedefs. You might try using the ecpg from a recent snapshot. (AFAIK it should be stable enough for production use, though I'd not recommend using anything else from development tip ...) regards, tom lane
On Fri, Jul 19, 2002 at 05:02:53PM -0400, Daniel Kelley wrote: > EXEC SQL BEGIN DECLARE SECTION; > typedef struct { > int id; > char name[30]; > char dsc[1000]; > } rec_t; > > rec_t r; > EXEC SQL END DECLARE SECTION; Actually this will not work, but you can do the following: EXEC SQL BEGIN DECLARE SECTION; struct { int id; char name[30]; char dsc[1000]; } r; EXEC SQL END DECLARE SECTION; or use the EXEC SQL TYPE command to do a typedef so ecpg knows about it: EXEC SQL TYPE rec_r is struct { int id; char name[30]; char dsc[1000]; } > is there are facility that i might be missing that would allow me to use > our existing structures as host variables w/ postgres embedded sql? or am > i better off just skipping ecpg and coding directly with libpq? That will be much more work. ecpg was modelled in a way that pro*c apps should compile without much of a problem. Michael -- Michael Meskes Michael@Fam-Meskes.De Go SF 49ers! Go Rhein Fire! Use Debian GNU/Linux! Use PostgreSQL!