examples in Precompiler user manual does not work

[Jenny Zhang]

I am trying to figure out how to execute dynamic SQL using SAPDB
precompiler.  I followed the example in the Precompiler user manual
section 2.10.3 'Dynamic SQL statement with descriptor' (page 2-45).

The attached is my .cpc program.  In line 36,
if I use 'exec sql execute dbt3_fetch', sqlca.sqlcode is -9405.
If I use 'exec sql execute dbt3_fetch using descriptor' sqlca.sqlcode is
100.  

set_decribe_area() seemed to work correctly.  My guess is something is
missing in the statement:
EXEC SQL prepare dbt3_fetch from 'fetch using descriptor'

Thanks in advance for your help,
-- 
Jenny Zhang
Open Source Development Lab Inc 
15275 SW Koll Parkway - Suite H
Beaverton, OR 97006
(503)626-2455 ext 31

#include <stdio.h>
#include <string.h>
EXEC SQL include sqlca;
void set_describe_area();
void get_output();

/* declare the host variables which are binded to sqlda */
double hostreal[10];
int hostint[5];
char hostchar40[10][41];
char hostchar117[1][118];
main()
{
  exec sql begin declare section;
  char stmt[1024];
  exec sql end declare section;

  exec sql set serverdb 'DBT3' on 'localhost';
  exec sql connect dbt identified by dbt;
  if (sqlca.sqlcode !=0) printf("sql returned error: %d\n", sqlca.sqlcode);

        strcpy(stmt, "select s_name from supplier where s_suppkey<10");

        EXEC SQL prepare dbt3_query from :stmt;
        EXEC SQL execute dbt3_query;

        EXEC SQL prepare dbt3_fetch from 'fetch using descriptor';
        EXEC SQL describe dbt3_fetch;
        printf("state 1 sqlcode %d\n",sqlca.sqlcode );

        /* provide the SQLDA with user information */
        set_describe_area();
        printf("state 2 sqlcode %d\n",sqlca.sqlcode );

        /* process the result table */
        EXEC SQL execute dbt3_fetch using descriptor;
        printf("state 4 sqlcode %d\n",sqlca.sqlcode );
        if (sqlca.sqlcode == 0)
        {
        printf("state 5\n");
                get_output();
        //      EXEC SQL execute dbt3_query;
        }
        printf("state 6\n");
        EXEC SQL close c_dbt3;
        
}

void set_describe_area()
{
        sqlvartype *actvar;
        int i, hostint_index, hostreal_index, hostchar40_index, hostchar117_index;

        hostint_index=0;
        hostreal_index=0;
        hostchar40_index=0;
        hostchar117_index=0;

        printf("sqlda.sqln is %d\n", sqlda.sqln);
        for (i=0; i<sqlda.sqln; i++)
        {
                printf("i is %d\n", i);
                actvar = &sqlda.sqlvar[i];
                printf("coltype %d\n", (*actvar).coltype);
                switch ((*actvar).coltype)
                {
                        case 0: 
                                if ((*actvar).colfrac == 0)
                                {
                                        (*actvar).hostvartype=1;
                                        (*actvar).hostvaraddr = 
&hostint[hostint_index];
                                        hostint_index++;
                                }
                                else
                                {
                                        (*actvar).collength=18;
                                        (*actvar).colfrac=8;
                                        (*actvar).hostvartype=3;
                                        (*actvar).hostvaraddr = 
&hostreal[hostreal_index];
                                        hostreal_index++;
                                }
                                break;
                        case 2: 
                                (*actvar).hostvartype = 6;
                                if ((*actvar).collength < 41)
                                {
                                        (*actvar).collength = 40;
                                        (*actvar).hostvaraddr = 
hostchar40[hostchar40_index];
                                        hostchar40_index++;
                                }
                                else
                                {
                                        (*actvar).collength = 117;
                                        (*actvar).hostvaraddr = 
hostchar117[hostchar117_index];
                                        hostchar117_index++;
                                }
                                break;
                        default:
                                printf("invalid type\n");
                }
        }
}

void get_output()
{
        int i;
        //for (i=0; i<10; i++)
                printf("id %d: s_name %s\n", i, hostchar40[0]);
}