Thread: pgsql embedded again!

hi.
  
 
I still have the data type problem.
  
 
I am working with the postgresql system catalog and I wanna get all
  
 
relname of pg_class relation on a C variable.

   
 
-----> \d pg_class

    Attribute   |   Type    | Modifier
    
 
--------------+-----------+----------
  relname      | name      |
   reltype      | oid       |
    relowner     | integer   |
     relam        | oid       |
      .........
       ......
        .....
         ...
          ..

            
 
C program.

   
 
EXEC SQL BEGIN DECLARE SECTION;
         VARCHAR tabla[50];    I also tried with char tabla[50];
          ......
           ....
            .
      
 
EXEC SQL END DECLARE SECTION;


     I used a cursor for results.....
     
 
EXEC SQL DECLARE T99 CURSOR FOR select relname from pg_class

   now I want to get the results of query... then:

               EXEC SQL OPEN T99;
                EXEC SQL FETCH IN T99 INTO :tabla; here is the problem, I can't
       
 
to get on tabla variable results.
  
 
I think that may be the data type ..... I don't know ....


     do you know about psql embedded mail list?
                                                     
 

Hi Esteban, 
Your problem looks familiar to me, 
and it seems you did not follow my advice. 
Anyway, here is a C sample program which works. 
It has nothing to do with wrong types, but with a 
missing connection, but see for yourself. 


/*
/opt/pgsql/bin/ecpg -o sampleprog01.c sampleprog01.sql
the compile command is for HP-UX - you have to adapt it for your machine 
cc -Aa +w1 -g -I/opt/pgsql/include/ -L/opt/pgsql/lib/ sampleprog01.c -Wl,-a,archive -lecpg -lpq -o sampleprog01

*/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "libpq-fe.h"

exec sql include sqlca;

void main()
{
EXEC SQL BEGIN DECLARE SECTION;   char       *dbName;   VARCHAR     tabla[50];    
EXEC SQL END DECLARE SECTION;   int nrows;
   dbName = "template1";


EXEC SQL CONNECT TO :dbName ; 
printf("sqlca.sqlcode = %d \n", sqlca.sqlcode) ; 

EXEC SQL BEGIN ; 
EXEC SQL DECLARE T99 CURSOR FOR select relname from pg_class ; 
          EXEC SQL OPEN T99;      for(nrows = 0;; nrows++) {             EXEC SQL FETCH IN T99 INTO :tabla;    if (
sqlca.sqlcode!= 0 )    break;   printf("%.*s \n", tabla.len, tabla.arr );       }       printf("nrows = %d ;
sqlca.sqlcode= %d \n", nrows, sqlca.sqlcode) ;              EXEC SQL CLOSE T99;   
 
EXEC SQL END ; 
EXEC SQL DISCONNECT ; 

}