Henry Manasseh created CASSANDRA-11533:
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Summary: Support creating and returning UDTs from a UDF
Key: CASSANDRA-11533
URL: https://issues.apache.org/jira/browse/CASSANDRA-11533
Project: Cassandra
Issue Type: Improvement
Components: Core
Reporter: Henry Manasseh
Priority: Minor
UDFs support returning UDTs. I see the various test cases which validate by
returning the parameter UDT as the return UDT (which works because it returns
an already existing UDTValue instance). But there is currently no way to create
a new instance of an UDTValue and return it.
It seems that to accomplish that it would require getting an instance of the
KeyspaceMetadata but that requires use of packages which are not white listed.
A solution could be to add a method to getUserType(String) which calls schema
in the super class org.apache.cassandra.cql3.functions.JavaUDF.
e.g.
protected UserType getUserType(String userTypeName) {
org.apache.cassandra.schema.KeyspaceMetadata ksm =
org.apache.cassandra.config.Schema.instance.getKSMetaData("test_ks");
com.datastax.driver.core.UserType myUdt =
ksm.types.get("my_other_udt").get();
return nyUdt;
}
To illustrate, I wrote a simple UDF to transform one UDT into another UDT. This
fails compilation because Schema is not whitelisted.
CREATE OR REPLACE FUNCTION test_ks.transform_udt (val my_udt)
RETURNS NULL ON NULL INPUT
RETURNS my_other_udt
LANGUAGE java
AS '
String fieldA = val.getString("field_a");
org.apache.cassandra.schema.KeyspaceMetadata ksm =
org.apache.cassandra.config.Schema.instance.getKSMetaData("test_ks");
com.datastax.driver.core.UserType myUdt =
ksm.types.get("my_other_udt").get();
com.datastax.driver.core.UDTValue transformedValue = myUdt.newValue();
transformedValue.setUUID("id", java.util.UUID.randomUUID());
transformedValue.setString("field_a", fieldA);
transformedValue.setString("field_b", "value b");
return transformedValue;
';
This is the error:
<stdin>:88:InvalidRequest: code=2200 [Invalid query] message="Could not compile
function 'test_ks.transform_udt' from Java source:
org.apache.cassandra.exceptions.InvalidRequestException: Java source
compilation failed:
Line 4: org.apache.cassandra.schema.KeyspaceMetadata cannot be resolved to a
type
Line 4: org.apache.cassandra.config.Schema.instance cannot be resolved to a type
"
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