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'
