Example: Referencing an External UDF - Advanced SQL Engine - Teradata Database

In this example, the SQL UDF named MySQLUDF references an external UDF named MyExtUDF in the RETURN statement.

Consider the following function definition and query:

   CREATE FUNCTION Test.MySQLUDF (a INT, b INT, c INT)
   RETURNS INT
   LANGUAGE SQL
   CONTAINS SQL
   DETERMINISTIC
   SQL SECURITY DEFINER
   COLLATION INVOKER
   INLINE TYPE 1
   RETURN a + b * MyExtUDF(a, b) - c;
   SELECT Test.MySQLUDF(t1.a1, t2.a2, t3.a3) FROM t1, t2, t3;

The user executing the SELECT statement must have the following privileges:

• SELECT privilege on tables t1, t2, and t3, their containing databases, or on the columns t1.a1, t2.a2, and t3.a3.
• EXECUTE FUNCTION privilege on MySQLUDF or on the database named Test.

Because the SQL UDF references MyExtUDF, the following privileges are also checked:

• The creator of MySQLUDF must exist and have the EXECUTE FUNCTION privilege on MyExtUDF or its containing database.
• The database named Test (the immediate owner of MySQLUDF) must have the EXECUTE FUNCTION privilege on MyExtUDF or its containing database.