Thread: numeric
Hi, i m writing a C module (extension), the procedure has a parameter that is of type numeric,
inside the function i can not read the parameter or so it seems, this what is do:
float8 db_balance,in_chgval;
in_chgval = PG_GETARG_FLOAT8(2);
elog(INFO,"in_chgval = %0.2f",in_chgval);
The above elog, always shows cero, more over, i m also trying to read a
numeric from the database and substracted from the in_chgval parameter,
the operation always gives 0,, so apparently i can not read a numeric from a
data base:
db_balance = DatumGetFloat8(SPI_getbinval(SPI_tuptable->vals[0],SPI_tuptable->tupdesc,1,&is_null));
elog(INFO,"db_balance(%f) - in_chgval(%f) = %f",db_balance,in_chgval,(db_balance - in_chgval));
it shows all 0 ..... please any advise would be really appreciated. thank you!!
inside the function i can not read the parameter or so it seems, this what is do:
float8 db_balance,in_chgval;
in_chgval = PG_GETARG_FLOAT8(2);
elog(INFO,"in_chgval = %0.2f",in_chgval);
The above elog, always shows cero, more over, i m also trying to read a
numeric from the database and substracted from the in_chgval parameter,
the operation always gives 0,, so apparently i can not read a numeric from a
data base:
db_balance = DatumGetFloat8(SPI_getbinval(SPI_tuptable->vals[0],SPI_tuptable->tupdesc,1,&is_null));
elog(INFO,"db_balance(%f) - in_chgval(%f) = %f",db_balance,in_chgval,(db_balance - in_chgval));
it shows all 0 ..... please any advise would be really appreciated. thank you!!
Hi, i m writing a C module (extension), the procedure has a parameter that is of type numeric,
inside the function i can not read the parameter or so it seems, this what is do:
float8 db_balance,in_chgval;
in_chgval = PG_GETARG_FLOAT8(2);
elog(INFO,"in_chgval = %0.2f",in_chgval);
The above elog, always shows cero, more over, i m also trying to read a
numeric from the database and substracted from the in_chgval parameter,
the operation always gives 0,, so apparently i can not read a numeric from a
data base:
db_balance = DatumGetFloat8(SPI_getbinval(SPI_tuptable->vals[0],SPI_tuptable->tupdesc,1,&is_null));
elog(INFO,"db_balance(%f) - in_chgval(%f) = %f",db_balance,in_chgval,(db_balance - in_chgval));
it shows all 0 ..... please any advise would be really appreciated. thank you!!
float8 db_balance,in_chgval;
in_chgval = PG_GETARG_FLOAT8(2);
elog(INFO,"in_chgval = %0.2f",in_chgval);
The above elog, always shows cero, more over, i m also trying to read a
numeric from the database and substracted from the in_chgval parameter,
the operation always gives 0,, so apparently i can not read a numeric from a
data base:
db_balance = DatumGetFloat8(SPI_getbinval(SPI_tuptable->vals[0],SPI_tuptable->tupdesc,1,&is_null));
elog(INFO,"db_balance(%f) - in_chgval(%f) = %f",db_balance,in_chgval,(db_balance - in_chgval));
it shows all 0 ..... please any advise would be really appreciated. thank you!!
"Juan Pablo L." <jpablolorenzetti@hotmail.com> writes:
> Hi, i m writing a C module (extension), the procedure has a parameter that is of type numeric,
> inside the function i can not read the parameter or so it seems, this what is do:
> float8 db_balance,in_chgval;
> in_chgval = PG_GETARG_FLOAT8(2);
> elog(INFO,"in_chgval = %0.2f",in_chgval);
If the C code is written that way, the function has to be declared to take
type float8 (a/k/a double precision), not numeric.
The parser will insert a conversion from numeric to float8 automatically,
so the function will still work with a numeric data column. You might
lose some precision in the conversion though.
regards, tom lane
thank you for your answer, the function is declared as:
FUNCTION wtt_discount_account(IN in_phonenumber varchar(20),IN in_balanceid integer,IN in_chgval numeric(10,2))
i chose numeric because is supposed to be better for numbers/money operations, supposed to be exact,
i would not want to loose precision because that is money, is there any other way which does not
involve loosing precision ? thankS!!
FUNCTION wtt_discount_account(IN in_phonenumber varchar(20),IN in_balanceid integer,IN in_chgval numeric(10,2))
i chose numeric because is supposed to be better for numbers/money operations, supposed to be exact,
i would not want to loose precision because that is money, is there any other way which does not
involve loosing precision ? thankS!!
> From: tgl@sss.pgh.pa.us
> To: jpablolorenzetti@hotmail.com
> CC: pgsql-general@postgresql.org
> Subject: Re: [GENERAL] numeric data type
> Date: Tue, 22 Sep 2015 16:07:36 -0400
>
> "Juan Pablo L." <jpablolorenzetti@hotmail.com> writes:
> > Hi, i m writing a C module (extension), the procedure has a parameter that is of type numeric,
> > inside the function i can not read the parameter or so it seems, this what is do:
>
> > float8 db_balance,in_chgval;
>
> > in_chgval = PG_GETARG_FLOAT8(2);
>
> > elog(INFO,"in_chgval = %0.2f",in_chgval);
>
> If the C code is written that way, the function has to be declared to take
> type float8 (a/k/a double precision), not numeric.
>
> The parser will insert a conversion from numeric to float8 automatically,
> so the function will still work with a numeric data column. You might
> lose some precision in the conversion though.
>
> regards, tom lane
> To: jpablolorenzetti@hotmail.com
> CC: pgsql-general@postgresql.org
> Subject: Re: [GENERAL] numeric data type
> Date: Tue, 22 Sep 2015 16:07:36 -0400
>
> "Juan Pablo L." <jpablolorenzetti@hotmail.com> writes:
> > Hi, i m writing a C module (extension), the procedure has a parameter that is of type numeric,
> > inside the function i can not read the parameter or so it seems, this what is do:
>
> > float8 db_balance,in_chgval;
>
> > in_chgval = PG_GETARG_FLOAT8(2);
>
> > elog(INFO,"in_chgval = %0.2f",in_chgval);
>
> If the C code is written that way, the function has to be declared to take
> type float8 (a/k/a double precision), not numeric.
>
> The parser will insert a conversion from numeric to float8 automatically,
> so the function will still work with a numeric data column. You might
> lose some precision in the conversion though.
>
> regards, tom lane
Juan Pablo L. wrote: > thank you for your answer, the function is declared as: > > FUNCTION wtt_discount_account(IN in_phonenumber varchar(20),IN in_balanceid integer,IN in_chgval numeric(10,2)) > > i chose numeric because is supposed to be better for numbers/money operations, supposed to be exact, > i would not want to loose precision because that is money, is there any other way which does not > involve loosing precision ? thankS!! What you need is to use PG_GETARG_NUMERIC, then, and use a Numeric * variable rather than float8. -- Álvaro Herrera http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
Hi Alvaro, thank you for your answer, PG_GETARG_NUMERIC does not exist .. cant find it in the source code and when running i get
undefined symbol: PG_GETARG_NUMERIC.
undefined symbol: PG_GETARG_NUMERIC.
> Date: Tue, 22 Sep 2015 18:11:26 -0300
> From: alvherre@2ndquadrant.com
> To: jpablolorenzetti@hotmail.com
> CC: tgl@sss.pgh.pa.us; pgsql-general@postgresql.org
> Subject: Re: [GENERAL] numeric data type
>
> Juan Pablo L. wrote:
> > thank you for your answer, the function is declared as:
> >
> > FUNCTION wtt_discount_account(IN in_phonenumber varchar(20),IN in_balanceid integer,IN in_chgval numeric(10,2))
> >
> > i chose numeric because is supposed to be better for numbers/money operations, supposed to be exact,
> > i would not want to loose precision because that is money, is there any other way which does not
> > involve loosing precision ? thankS!!
>
> What you need is to use PG_GETARG_NUMERIC, then, and use a Numeric *
> variable rather than float8.
>
> --
> Álvaro Herrera http://www.2ndQuadrant.com/
> PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
> From: alvherre@2ndquadrant.com
> To: jpablolorenzetti@hotmail.com
> CC: tgl@sss.pgh.pa.us; pgsql-general@postgresql.org
> Subject: Re: [GENERAL] numeric data type
>
> Juan Pablo L. wrote:
> > thank you for your answer, the function is declared as:
> >
> > FUNCTION wtt_discount_account(IN in_phonenumber varchar(20),IN in_balanceid integer,IN in_chgval numeric(10,2))
> >
> > i chose numeric because is supposed to be better for numbers/money operations, supposed to be exact,
> > i would not want to loose precision because that is money, is there any other way which does not
> > involve loosing precision ? thankS!!
>
> What you need is to use PG_GETARG_NUMERIC, then, and use a Numeric *
> variable rather than float8.
>
> --
> Álvaro Herrera http://www.2ndQuadrant.com/
> PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
Juan Pablo L. wrote: > Hi Alvaro, thank you for your answer, PG_GETARG_NUMERIC does not exist .. cant find it in the source code and when runningi get > undefined symbol: PG_GETARG_NUMERIC. #include "utils/numeric.h" -- Álvaro Herrera http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
Alvaro, thank you, that worked.
> Date: Tue, 22 Sep 2015 18:57:38 -0300
> From: alvherre@2ndquadrant.com
> To: jpablolorenzetti@hotmail.com
> CC: tgl@sss.pgh.pa.us; pgsql-general@postgresql.org
> Subject: Re: [GENERAL] numeric data type
>
> Juan Pablo L. wrote:
> > Hi Alvaro, thank you for your answer, PG_GETARG_NUMERIC does not exist .. cant find it in the source code and when running i get
> > undefined symbol: PG_GETARG_NUMERIC.
>
> #include "utils/numeric.h"
>
>
> --
> Álvaro Herrera http://www.2ndQuadrant.com/
> PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
> From: alvherre@2ndquadrant.com
> To: jpablolorenzetti@hotmail.com
> CC: tgl@sss.pgh.pa.us; pgsql-general@postgresql.org
> Subject: Re: [GENERAL] numeric data type
>
> Juan Pablo L. wrote:
> > Hi Alvaro, thank you for your answer, PG_GETARG_NUMERIC does not exist .. cant find it in the source code and when running i get
> > undefined symbol: PG_GETARG_NUMERIC.
>
> #include "utils/numeric.h"
>
>
> --
> Álvaro Herrera http://www.2ndQuadrant.com/
> PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services