HANA database - Injection of a Table User Defined Function into a lateral join - hana

Question

In short
On an HANA database, I have set a Table User Defined Function which returns a 1-row table with 3 columns ;
I would like to use it inside a lateral join but so far my attempts have been to no avail.
The problem
Let's say we have the following dummy Table User Defined Function :
CREATE OR REPLACE FUNCTION PBANALYST. F__ITEM_MBEW(
IN
p_str_MATNR NVARCHAR(18)
, p_str_BWKEY NVARCHAR(02)
, p_str_VALDATE NVARCHAR(08)
)
RETURNS
TABLE(
VALDATE NVARCHAR(08)
, LBKUM INTEGER
, VERPR DECIMAL
, STPRS DECIMAL
)
LANGUAGE SQLSCRIPT
SQL SECURITY INVOKER
AS
BEGIN
RETURN
SELECT
'20220928' AS VALDATE
, 10 AS LBKUM
, 5.3 AS VERPR
, 10.5 AS STPRS
FROM DUMMY
;
END;
It works fine on its own.
But when I try to inject it inside a lateral join, I get an error :
DO
BEGIN
tbl_MATNR_LIST =
SELECT '000000000000824151' AS MATNR , '92' AS div , '20220715' AS VALDATE FROM dummy
;
SELECT
tbl_MATNR_LIST. *
FROM :tbl_MATNR_LIST tbl_MATNR_LIST ,
LATERAL(
SELECT *
FROM F__ITEM_MBEW(
'000000000000824151'
, '92'
, '20220715'
)
) MBEW
;
END;
DataSource.Error : ODBC: ERROR [S1000] [SAP AG][LIBODBCHDB DLL][HDBODBC] General error;318 decimal precision specifier is out of range: -1: (1 to 38)
How can I fix it?
Thank you for your help.

Answer 1

The error message
DataSource.Error : ODBC: ERROR [S1000] [SAP AG][LIBODBCHDB DLL][HDBODBC] General error;318 decimal precision specifier is out of range: -1: (1 to 38)
can easily be fixed by specifying the decimal data type lengths in the user defined function:
TABLE(
VALDATE NVARCHAR(08)
, LBKUM INTEGER
, VERPR DECIMAL (10, 2)
, STPRS DECIMAL (10, 2)
)
Unfortunately, that does not help with the overall goal: to use the UDF in the LATERAL join in a meaningful way.
What does work is something like this:
DO
BEGIN
tbl_MATNR_LIST =
SELECT '000000000000824151' AS MATNR
, '92' AS div
, '20220715' AS VALDATE
FROM dummy;
SELECT
tml. *
FROM :tbl_MATNR_LIST tml
CROSS JOIN LATERAL(
F__ITEM_MBEW( '000000000000824151'
, '92'
, '20220715')
) MBEW;
END;
This does return the result, but obviously does not use any "lateral" references.
If one tries to make "grab stuff side-ways" this is the result:
[...]
CROSS JOIN LATERAL(
F__ITEM_MBEW( '000000000000824151'
, tml.div
, '20220715')
) MBEW;
[...]
SQL Error [7] [HY000]: SAP DBTech JDBC: [7] (at 292): feature not supported: non-field expression with LATERAL: line 13 col 29 (at pos 292)
At this point, I would guess that this way of using the LATERAL JOIN is just not supported (on version 2.00.057).