The following documentation comment has been logged on the website:
Page: https://www.postgresql.org/docs/13/ecpg-variables.html
Description:
Without this line:
EXEC SQL WHENEVER NOT FOUND CONTINUE;
after the while(1), I find that ECPG CURSOR examples fail.
For example, this example under 36.4.4.3.2. Structures fails:
EXEC SQL BEGIN DECLARE SECTION;
typedef struct
{
int oid;
char datname[65];
long long int size;
} dbinfo_t;
dbinfo_t dbval;
EXEC SQL END DECLARE SECTION;
memset(&dbval, 0, sizeof(dbinfo_t));
EXEC SQL DECLARE cur1 CURSOR FOR SELECT oid, datname,
pg_database_size(oid) AS size FROM pg_database;
EXEC SQL OPEN cur1;
/* when end of result set reached, break out of while loop */
EXEC SQL WHENEVER NOT FOUND DO BREAK;
while (1)
{
/* Fetch multiple columns into one structure. */
EXEC SQL FETCH FROM cur1 INTO :dbval;
/* Print members of the structure. */
printf("oid=%d, datname=%s, size=%lld\n", dbval.oid, dbval.datname,
dbval.size);
}
EXEC SQL CLOSE cur1;