MQRECEIVEALLCLOB

The MQRECEIVEALLCLOB function returns a table that contains the messages and message metadata from a specified MQSeries® location with a CLOB column with removal of the messages from the queue.

Notes:

¹ The comma is required before num-rows when any of the preceding arguments to the function are specified.

The MQRECEIVEALLCLOB function returns a table containing the messages and message metadata from the MQSeries location that is specified by receive-service, using the quality-of-service policy that is defined in service-policy. Performing this operation removes the messages from the queue that is associated with receive-service.

receive-service

An expression that returns a value that is a built-in character string or graphic string data type that is not a LOB. The value of the expression must not be an empty string or a string with trailing blanks. The expression must have an actual length that is no greater than 48 bytes. The value of the expression must refer to a service point that is defined in the SYSIBM.MQSERVICE table. A service point is a logical end-point from where a message is sent or received. Service point definitions include the name of the MQSeries queue manager and queue. For more information about MQSeries Application Messaging, see SQL Programming.

If receive-service is not specified or the null value, DB2®.DEFAULT.SERVICE is used.

service-policy

An expression that returns a value that is a built-in character string or graphic string data type that is not a LOB. The value of the expression must not be an empty string or a string with trailing blanks. The expression must have an actual length that is no greater than 48 bytes. The value of the expression must refer to a service policy that is defined in the SYSIBM.MQPOLICY table. A service policy specifies a set of quality-of-service options that are to be applied to this messaging operation. These options include message priority and message persistence. For more information about MQSeries Application Messaging, see SQL Programming.

If service-policy is not specified or the null value, DB2.DEFAULT.POLICY is used.

correl-id

An expression that returns a value that is a built-in character string or graphic string data type that is not a LOB. The expression must have an actual length that is no greater than 24 bytes. The value of the expression specifies the correlation identifier that is associated with this message. A correlation identifier is often specified in request-and-reply scenarios to associate requests with replies. The first message with a matching correlation identifier is returned. For more information about MQSeries Application Messaging, see SQL Programming.

A fixed length string with trailing blanks is considered a valid value. However, when the correl-id is specified on another request such as MQSEND, the identical correl-id must be specified to be recognized as a match. For example, specifying a value of 'test' for correl-id on MQRECEIVEALLCLOB does not match a correl-id value of 'test ' (with trailing blanks) specified earlier on an MQSEND request.

If correl-id is not specified or is an empty string or the null value, a correlation identifier is not used, and the message at the beginning of the queue is returned.

num-rows

An expression that returns a value that is a SMALLINT or INTEGER data type whose value is a positive integer or zero. The value of the expression specifies the maximum number of messages to return.

If num-rows is not specified or the value of expression is zero, all available messages are returned.

The result of the function is a table with the format shown in the following table. All the columns are nullable.

Table 1. Format of the resulting table for MQRECEIVEALLCLOB
Column name	Data type	Contains
MSG	CLOB(2M)	The contents of the MQSeries message
CORRELID	VARCHAR(24)	The correlation ID that is used to relate messages
TOPIC	VARCHAR(40)	Reserved
QNAME	VARCHAR(48)	The name of the queue from which the message was received
MSGID	VARCHAR(24)	The unique, MQSeries-assigned identifier for the message
MSGFORMAT	VARCHAR(8)	The format of the message, as defined by MQSeries

The CCSID of the result columns, except for CORRELID and MSGID, is the default CCSID at the current server.

Notes

Prerequisites: In order to use the MQSeries functions, IBM® MQSeries for IBM i must be installed, configured, and operational.

Example

This example receives all the messages from the queue specified by the default service (DB2.DEFAULT.SERVICE), using the default policy (DB2.DEFAULT.POLICY). The messages and all the metadata are returned as a table.
```
  SELECT *
   FROM TABLE (MQRECEIVEALLCLOB ()) AS T
   
```
This example receives all the messages from the head of the queue specified by the service MYSERVICE, using the default policy (DB2.DEFAULT.POLICY). Only the MSG and CORRELID columns are returned.
```
  SELECT T.MSG, T.CORRELID 
   FROM TABLE (MQRECEIVEALLCLOB ('MYSERVICE')) AS T
   
```
This example receives all of the message from the head of the queue specified by the service "MYSERVICE", using the policy "MYPOLICY". Only messages with a CORRELID of '1234' are returned. Only the MSG and CORRELID columns are returned.
```
  SELECT *
   FROM TABLE (MQRECEIVEALLCLOB ('MYSERVICE','MYPOLICY','1234')) AS T
   
```
This example receives the first 10 messages from the head of the queue specified by the default service (DB2.DEFAULT.SERVICE), using the default policy (DB2.DEFAULT.POLICY). All columns are returned.
```
  SELECT *
   FROM TABLE (MQRECEIVEALLCLOB (10)) AS T
```