Hey all, I'm working on some server-side C code that involves a few calculations on a numeric value. The calculation is along the lines of: (numeric) result = (numeric) value * ((int) base ^ (int) power); What's the usual approach to write functions like these? This is how far I got: #include <postgres.h> #include <fmgr.h> #include <executor/spi.h> #include <executor/executor.h> #include <utils/numeric.h> #include <utils/builtins.h> PG_FUNCTION_INFO_V1(unit_product__aggregate_state); Datum unit_product__aggregate_state(PG_FUNCTION_ARGS) { Datum state = PG_GETARG_DATUM(0); HeapTupleHeader t = PG_GETARG_HEAPTUPLEHEADER(1); Datum base, scale, exponent; Datum result; bool isNull; base = GetAttributeByName(t, "base", &isNull); if (isNull) PG_RETURN_NULL(); scale = GetAttributeByName(t, "scale", &isNull); if (isNull) PG_RETURN_NULL(); exponent = GetAttributeByName(t, "exponent", &isNull); if (isNull) PG_RETURN_NULL(); /* state *= base ^ (scale * exponent) */ result = DirectFunctionCall2(int4mul, scale, exponent); result = DirectFunctionCall2(numeric_power, base, result); result = DirectFunctionCall2(numeric_mul, state, result); PG_RETURN_NUMERIC(result); } But it crashes the server, probably because I'm passing ints where numerics are expected. Is this the right approach at all? And if so, how am I supposed to cast those ints to numerics? Are there any examples around for dealing with numerics? The stuff in the documentation (http://www.postgresql.org/docs/8.4/interactive/xfunc-c.html) conveniently omits numerics, so I had to dig through doxygen to get as far as I am now... Regards, Alban Hertroys -- Screwing up is the best way to attach something to the ceiling. !DSPAM:737,4b74028910442077341801! -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general