mqCountItems

The mqCountItems call returns the number of occurrences of user items, system items, or both, that are stored in a bag with the same specific selector.

Syntax for mqCountItems

mqCountItems (Bag, Selector, ItemCount, CompCode, Reason)

Parameters for mqCountItems

Bag (MQHBAG) - input

Handle of the bag with items that are to be counted. This can be a user bag or a system bag.

Selector (MQLONG) - input

Selector of the data items to count.

If the selector is less than zero (a system selector), the selector must be one that is supported by the MQAI. MQRC_SELECTOR_NOT_SUPPORTED results if it is not.

If the specified selector is not present in the bag, the call succeeds and zero is returned for ItemCount.

The following special values can be specified for Selector:

MQSEL_ALL_SELECTORS

All user and system items are to be counted.

MQSEL_ALL_USER_SELECTORS

All user items are to be counted; system items are excluded from the count.

MQSEL_ALL_SYSTEM_SELECTORS

All system items are to be counted; user items are excluded from the count.

ItemCount (MQLONG) - output

Number of items of the specified type in the bag (can be zero).

CompCode (MQLONG) - output

Completion code.

Reason (MQLONG) - output

Reason code qualifying CompCode. The following reason codes indicating error conditions can be returned from the mqCountItems call:

MQRC_HBAG_ERROR

Bag handle not valid.

MQRC_ITEM_COUNT_ERROR

ItemCount parameter not valid (invalid parameter address).

MQRC_SELECTOR_NOT_SUPPORTED

Specified system selector not supported by the MQAI.

MQRC_SELECTOR_OUT_OF_RANGE

Selector not within valid range for call.

Usage notes for mqCountItems

This call counts the number of data items, not the number of unique selectors in the bag. A selector can occur multiple times, so there might be fewer unique selectors in the bag than data items.

C language invocation for mqCountItems

mqCountItems (Bag, Selector, &ItemCount, &CompCode, &Reason);

MQHBAG  Bag;            /* Bag handle */
MQLONG  Selector;       /* Selector */
MQLONG  ItemCount;      /* Number of items */
MQLONG  CompCode;       /* Completion code */
MQLONG  Reason;         /* Reason code qualifying CompCode */

Visual Basic invocation for mqCountItems

(Supported on Windows only.)

mqCountItems Bag, Selector, ItemCount, CompCode, Reason

Dim Bag;      As Long 'Bag handle'
Dim Selector  As Long 'Selector'
Dim ItemCount As Long 'Number of items'
Dim CompCode  As Long 'Completion code'
Dim Reason    As Long 'Reason code qualifying CompCode'