Hello
I use Hive on Spark and have an issue with assigning several aliases to the output (several return values) of an UDF. I ran in several issues and ended up with a workaround (described at the end of this message). - Is assigning several aliases to the output of an UDF not supported by Spark SQL yet? - Is there a smarter solution than the one I ended up with finally - see (3)? 1) The query with following syntax is rejected due to the assigment of multiple aliases. Query -------- SELECT my_function(param_one, param_two) AS (return_one, return_two, return_three) FROM my_table; Error -------- Unsupported language features in query: SELECT my_function(param_one, param_two) AS (return_one, return_two, return_three) FROM my_table; TOK_QUERY TOK_FROM TOK_TABREF TOK_TABNAME my_table TOK_SELECT TOK_SELEXPR TOK_FUNCTION my_function TOK_TABLE_OR_COL param_one TOK_TABLE_OR_COL param_two return_one return_two return_three 2) Because of this error I searched for a way to avoid assigning multiple aliases to the UDF. I ended up having the following query and encountered another error/issue. Note: This error only occurs when having "c_0" in select clause. Only selecting "c_1" and "c_2" works fine. Query -------- SELECT return.c_0 AS return_one, return.c_1 AS return_two, return.c_2 AS return_three FROM (SELECT my_function(param_one, param_two) FROM my_table) return; Error -------- java.lang.RuntimeException: Couldn't find c_0#504 in [c_0#521L,c_1#522,c_2#523] 3) My final (working) workaround is wrapping the actual query (the one with the UDF) with an additional select statement. Query -------- SELECT result.c_0 AS return_one, result.c_1 AS return_two, result.c_2 AS return_three FROM(SELECT * FROM (SELECT my_function(param_one, param_two) FROM my_table) return) result; Error -------- No error :) Kind regards Max -- View this message in context: http://apache-spark-user-list.1001560.n3.nabble.com/Spark-SQL-Assigning-several-aliases-to-the-output-several-return-values-of-an-UDF-tp21238.html Sent from the Apache Spark User List mailing list archive at Nabble.com. --------------------------------------------------------------------- To unsubscribe, e-mail: user-unsubscr...@spark.apache.org For additional commands, e-mail: user-h...@spark.apache.org