Create UDAF
pom.xml
Add this to pom (probably you have to add the jar yourself to your repository. Look for the jar in /modules/system/layers/dv/org/jboss/teiid/api/main/teiid-api-9.1.2.jar . See http://javari.blogspot.pt/2009/10/instalar-um-jar-no-repositorio-maven.html):
<dependencies> <dependency> <groupId>org.jboss.teiid</groupId> <artifactId>teiid-api</artifactId> <version>9.1.2</version> </dependency> </dependencies>
Implement UDAF
package my.udaf; import org.teiid.CommandContext; import org.teiid.UserDefinedAggregate; public class MyAggregateFunction implements UserDefinedAggregate{ public MyAggregateFunction(){ reset(); } public void addInput(Long val, char separator){ // Use val (in this case Long) in someway. Example: add it to a list. } @Override public void reset(){ group = new ArrayList<>(); separator = null; } @Override public String getResult(CommandContext commandContext){
// do your work. Use all inputs and return them as you want.
}
}
Create Artifact
mvn clean install
Create Module
Here are the steps necessary to create a module in Teiid 9.1.2:Run the following in the server console (in
./jboss-cli.sh --connect
and run the following commands:
module add --name=module_name --resources=udaf-1.0.jar --dependencies=org.jboss.teiid.api
:reload
Where:
- module_name - Name of th module. We will use this name in vdb's;
- udaf-1.0.jar - Jar being added
- org.jboss.teiid.api - The udaf jar depends of this module.
Use UDAF in a VDB
<vdb name="MyVdb" version="1">
<description>My VDB</description>
<property name ="lib" value ="module_name "></property>
<metadata type="DDL"><![CDATA[
CREATE VIRTUAL FUNCTION MyAggregateFunction(val long, separator char) RETURNS string OPTIONS (JAVA_CLASS 'my.udaf.MyAggregateFunction', JAVA_METHOD 'addInput', AGGREGATE 'true', "NULL-ON-NULL" 'true', "ALLOWS-DISTINCT" 'true');
]]>
</metadata>
</model>
...
<model name="CountryServiceList" type="VIRTUAL">
<metadata type="DDL"><![CDATA[
CREATE VIEW my_view (
column_1 varchar(10),
column_2 varchar(10),
column_3 varchar(100),
)
AS
SELECT MyAggregateFunction(DISTINCT column_1, ',') as column_1,
column_2 ,
column_3
FROM my_table
GROUP BY column_1 , column_2
]]>
</metadata>
</model>
