Re: ECPG: non-integer constant in group by

Joachim Wieland wrote:
> On Fri, Sep 15, 2006 at 02:40:49AM -0800, Poul Jensen wrote:
>
>> 1) It seems like the fastest way to find the # of distinct elements in a
>> column is using GROUP BY. With ECPG, if I try
>>    EXEC SQL SELECT filenm FROM beamdata GROUP BY filenm;
>>    I will get "sql error Too few arguments". Why? Can I correct the
>> query to avoid the error message? (sqlca.sqlerrd[2] does contain the #
>> of elements in spite of error)
>>
> The problem is that you are selecting a value but you don't say where ecpg
> should store the result. You're missing the "INTO :var" part.
>
Thank you; that makes sense. I'm not sure why it's considered an error
though. Documentation says "Any SQL command can be run...", and why not.

The other problem I posted is worse and is what's really keeping me
stuck. Why are my text strings considered unacceptable "non-integer
constants"? Here are the relevant lines of code:

#define NVARS 24

EXEC SQL BEGIN DECLARE SECTION;
char *vars[NVARS] = { "filenm", "yr", "mo", "dy", "hr", "mt", "sc",
             "us", "stat_id", "bmnum", "channel", "scnflag",
             "cp_id", "intt", "intt_us", "frang", "rsep",
             "tfreq", "noise", "natten", "nave", "nrang",
             "gsct", "isct" };
char *stmt = "SELECT ? FROM beamdata GROUP BY ?;";
EXEC SQL END DECLARE SECTION;

EXEC SQL PREPARE query FROM :stmt;

for (i=0; i<NVARS; i++)
{
   EXEC SQL EXECUTE query USING :vars[i], :vars[i];
}

Fails at EXECUTE with error message:
sql error 'non-integer constant in GROUP BY'