Author: Written by Bruce Momjian (
<pgman@candle.pha.pa.us>) and last updated 2000-03-30
pgeasy allows you to cleanly interface to the libpq library, more like a 4GL SQL interface. Refer to Chapter 1 for more information about libpq
It consists of set of simplified C functions that encapsulate the functionality of libpq. The functions are:
PGresult *doquery(char *query);
PGconn *connectdb(char *options);
void disconnectdb();
int fetch(void *param,...);
int fetchwithnulls(void *param,...);
void reset_fetch();
void on_error_continue();
void on_error_stop();
PGresult *get_result();
void set_result(PGresult *newres);
void unset_result(PGresult *oldres);
Many functions return a structure or value, so you can do more work with the result if required.
   You basically connect to the database with connectdb,
   issue your query with doquery,
   fetch the results with fetch,
   and finish with disconnectdb.
  
   For SELECT queries, fetch
   allows you to pass pointers as parameters, and on return the variables
   are filled with data from the binary cursor you opened.  These binary
   cursors cannot be used if you are running the
   pgeasy
   client on a system with a different architecture than the database
   server.  If you pass a NULL pointer parameter, the column is skipped.
   fetchwithnulls allows you to retrieve the NULL
   status of the field by passing an int*
   after each result pointer, which returns true or false if the field is null.
   You can always use libpq functions on the PGresult pointer returned
   by doquery.
   reset_fetch starts the fetch back at the beginning.
  
   get_result,
   set_result,
   and
   unset_result
   allow you to handle multiple result sets at the same time.
  
There are several demonstration programs in the source directory.