Calling a java class from teiid trigger

rokhmanov Jul 18, 2012 12:12 PM

Hi,

Is it possible to call some java code by teiid trigger event? The closest approach I have in mind - have a trigger to call a custom translator (which will call a java code). Something like this:

"alter trigger on SmallA_2589 instead of insert as for each row begin atomic call custom.test123(new.col1, new.col2) ; end" - where "custom.test123" represents a custom translator.

Is there any better way?

Thanks,

Andriy

1. Re: Calling a java class from teiid trigger

rareddy Jul 18, 2012 1:22 PM (in response to rokhmanov)

You can use User Defined Function (UDF). A UDF is defined on a view model, and implementation is provided through Java code. See https://docs.jboss.org/author/display/TEIID/User+Defined+Functions

When you define the function like "test123" on the translator it is called "source or pushdown" function, it upto the translator to handle it in translator layer or really push down to source for evaluation. Look the ExecutionFactory class's "addPushDownFunction" method. Also, when the query is passed to translator for evaluation, you need to provide hooks to evaluate and return right results.

Ramesh..
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2. Re: Calling a java class from teiid trigger

shawkins Jul 18, 2012 1:48 PM (in response to rokhmanov)

Andriy,

We hook into Java either through a translator or a UDF. You're choice would mostly be about calling style, function/procedure/table abstraction. If you don't need a result set and only have in parameters then you can use function.

Steve
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3. Re: Calling a java class from teiid trigger

rokhmanov Jul 18, 2012 2:35 PM (in response to shawkins)

Thanks Steve and Ramesh. I want to do something with the results of continuous execution (fire some actions based on conditions). I think calling UDF from trigger is exactly what I need.
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