jdbc:outbound-gateway query only

[cromark]

trying to use jdbc:outbound-gateway to execute just a SQL query without an update, however schema requires an SQL update
can i just execute a query and send the resultset to the reply-channel

For example

<jdbc:outbound-gateway query="select * from foo" 
	 request-channel="jdbcParametersChannel" reply-channel="resultSetChannel" 
        data-source="dataSource" />

[Mark Fisher]

So, I guess the use-case is that you want the query to be executed based on a trigger message? Otherwise, if you have a scheduled trigger, you could perform the query with a JDBC inbound adapter.

[cromark]

my test case is using si:gateway to connect to jdbc:gateway. The resultset from jdbc:gateway is sent to reply channel of si:gateway.

it is a client initiated request-reply pattern rather than a poller request

[anshumania]

So, I guess the use-case is that you want the query to be executed based on a trigger message? Otherwise, if you have a scheduled trigger, you could perform the query with a JDBC inbound adapter.

if the use case is the former how do we go abt it ? i.e. execute a query based on a trigger message and use the resultset to trigger another service in a workflow ?

[Mark Fisher]

Can you briefly describe the triggering situation for your particular app... ie. when the query should be executed?

[anshumania]

Can you briefly describe the triggering situation for your particular app... ie. when the query should be executed?

Thanks for the quick reply.

I am polling a file directory for files and based on the file name have to check whether these exist in a database based on which i have to continue further processing in the workflow.

<int-file:inbound-channel-adapter id="inputPublicationFiles"
    directory="someRemoteDirectory" auto-create-directory="false"
    filename-pattern="*.somepattern">
    <int:poller id="poller" fixed-rate="1000"></int:poller>

<!-- just the filenames -->
 <int:transformer input-channel="inputPublicationFiles"
    expression="payload.name" output-channel="processPublicationFiles"></int:transformer>

  <int-jdbc:outbound-gateway request-channel="processPublicationFiles" query="select 'fileName' from someTable" reply-channel="processedPublicationFiles" data-source="dataSource"
  update="required ..?"></int-jdbc:outbound-gateway>

[anshumania]

will this be possible in the current spring architecture ?

Thanks for the quick reply.

I am polling a file directory for files and based on the file name have to check whether these exist in a database based on which i have to continue further processing in the workflow.

<int-file:inbound-channel-adapter id="inputPublicationFiles"
    directory="someRemoteDirectory" auto-create-directory="false"
    filename-pattern="*.somepattern">
    <int:poller id="poller" fixed-rate="1000"></int:poller>

<!-- just the filenames -->
 <int:transformer input-channel="inputPublicationFiles"
    expression="payload.name" output-channel="processPublicationFiles"></int:transformer>

  <int-jdbc:outbound-gateway request-channel="processPublicationFiles" query="select 'fileName' from someTable" reply-channel="processedPublicationFiles" data-source="dataSource"
  update="required ..?"></int-jdbc:outbound-gateway>

[anshumania]

For now am using a serviceActivator to invoke a JDBC template to do the same.
However i was still wondering if this gateway would be able to support the above scenario or why not ? Invoking a jdbc request to select a few items from a db based on an event and send them to another channel seems to be part of the event driven architecture scenario or not ?

[jweinercrt]

Any resolution on this? I am new to Spring Integration and likewise it seems to me that the outbound gateway should support select only. Thanks!

[Mark Fisher]

Please raise a new JIRA issue requesting that the UPDATE be optional for a JDBC outbound-gateway.

However, for a case like this where the inbound Message would be nothing more than a trigger (it contains no information needed for the action to be taken), it might be worth considering a more general new feature (one that has been discussed before but not implemented). We could have any inbound-channel-adapter with a trigger-channel as an alternative to the poller... or perhaps the <poller> itself would have a trigger channel rather than a fixed-rate/fixed-delay/cron or Trigger reference.