gtpc2mhdC/C++ Language Support User's Guide

TO2_getListDScollections-Retrieve the Data Store System Collections

This function returns a temporary sequence collection that contains a list of the persistent identifiers (PIDs) for the system collections in a specified data store.

Format

#include <c$to2.h>
long TO2_getListDScollections (TO2_PID_PTR   pid_ptr,
                               TO2_ENV_PTR   env_ptr,
                               const char    dsname[TO2_MAX_DSNAME]);

pid_ptr
A pointer to the field that holds the returned temporary PID assigned to the temporary sequence collection created in response to this request.

env_ptr
A pointer to the environment as returned by the TO2_createEnv function.

Normal Return

A positive value. The sequence collection referred to by pid_ptr contains one element per system collection. The format of the data area of the element is as follows:

struct  TO2_dsCollection_element
{
    TO2_PID collectionPID[TO2_MAX_PID_SIZE];
};

Error Return

A value of zero. Use the TO2_getErrorCode function to determine the specific error code. For more information, see Error Handling.

Programming Considerations

Enter an explicit TO2_deleteCollection function call when you have completed processing the returned temporary collection even though the temporary collection is automatically deleted when the entry control block (ECB) exits. This action ensures that system resources used by that collection are cleanly released back to the system for reuse.

Examples

The following example retrieves the sequence collection of data store system collections for data store CUSTOMER.

#include <c$to2.h>             /* Needed for TO2 API functions    */
#include <stdio.h>             /* APIs for standard I/O functions */
 
TO2_PID        pid;            /* Placeholder for temporary collect */
TO2_ENV_PTR    env_ptr;        /* Pointer to TO2 environment      */
char           dsname[TO2_MAX_DSNAME]="CUSTOMER";

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if (TO2_getListDScollections(&pid, env_ptr, dsname) ==TO2_ERROR) { printf("TO2_getListDScollections failed!\n); process_error(env_ptr); } else { printf("TO2_getListDScollections successful!\n"); }

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