org.apache.samza.sql.udfs

Interface ScalarUdf<T>

public interface ScalarUdf<T>

The base class for the Scalar UDFs. All the scalar UDF classes needs to extend this and implement a method named "execute". The number and type of arguments for the execute method in the UDF class should match the number and type of fields used while invoking this UDF in SQL statement. Say for e.g. User creates a UDF class with signature int execute(int var1, String var2). It can be used in a SQL query select myudf(id, name) from profile In the above query, Profile should contain fields named 'id' of INTEGER/NUMBER type and 'name' of type VARCHAR/CHARACTER

Method Summary

Modifier and Type	Method and Description
T	execute(java.lang.Object... args) Actual implementation of the udf function
void	init(Config udfConfig) Udfs can implement this method to perform any initialization that they may need.

Method Detail

init

void init(Config udfConfig)

Udfs can implement this method to perform any initialization that they may need.

Parameters:

udfConfig - Config specific to the udf.

execute

T execute(java.lang.Object... args)

Actual implementation of the udf function

Parameters:

args - list of all arguments that the udf needs

Returns:

Return value from the scalar udf.