16.20 - Variable Mode Table UDFs - Advanced SQL Engine - Teradata Database

Teradata Vantage™ - SQL External Routine Programming

Advanced SQL Engine
Teradata Database
Release Number
Release Date
April 2020
Content Type
Programming Reference
Publication ID
English (United States)

This section provides guidelines on how to write a Java method for a table UDF that can handle an invocation where the SELECT statement specifies columns from a derived table as input arguments. For example, the following statement invokes table_function_2 using column_1 from the preceding derived table with the t1 correlation name:

FROM ( SELECT column_1
       FROM table_1
       WHERE column_2 > 65 ) AS t1,
     TABLE (table_function_2(t1.column_1)) AS t2 (c1, c2, c3)
WHERE t1.column_3 = t2.c3;
Although this section discusses how to implement a method that only handles variable input arguments, you can write a method that can handle constant and variable input arguments. For details on constant mode table UDFs, see Constant Mode Table UDFs.