INPUT a List to stored procedure - sql

Question

I get a list of elments from R and I have to obtain the records from database that belong to a the list of elements.
INPUT:
'12345','23456', '34567', '45678'
PROCEDURE:
CREATE PROCEDURE "SCHEMA"."GET_RECORDS" (IN LIST (Type), OUT RECORDS tt_records)
LANGUAGE SQLSCRIPT
SQL SECURITY INVOKER
READS SQL DATA AS
BEGIN
RECORDS = select * from TABLE where ids in :LIST
END;
How can I provide such a list to the proceudre?

Answer 1

Handing over lists of parameters to SQLScript is a bit tricky as there is no straight-forward native construct for that.
One way to do it is to use the APPLY_FILTER function and to "smuggle" the list as a string parameter.
In my example I read from a table CUSERS and I create a filter condition for APPLY_FILTER that filters column USER_ID via an IN ( ) clause.
Removing the single quotes (' ') from the list is to avoid implicit type conversion when executing the query. Leaving the single quotes in place would make the IN () clause make look like this:
IN ( '<1st value>', '<2nd value>', '<3rd value>', ...)
instead of
IN (<1st value>, <2nd value>, <3rd value>, ...).
CREATE PROCEDURE "GET_RECORDS" (IN id_list VARCHAR(4000)
, OUT RECORDS tt_cusers)
LANGUAGE SQLSCRIPT
SQL SECURITY INVOKER
READS SQL DATA AS
BEGIN
declare _filter VARCHAR(4000);
_users = select * from cusers;
-- APPLY_FILTER expects a proper WHERE condition, so adding the column to filter
-- and the IN () expression is necessary.
--
-- the the id_list comes in with single quotes, let's remove those
_filter = 'USER_ID in (' || replace (:id_list, '''', '') ||')';
RECORDS = APPLY_FILTER(:_users, :_filter);
end;
call get_records (?, ?)
-- this 'list' is to be used as a single parameter value
-- '131072', '161223', '131074'
A slightly more comfortable approach for getting the data out from SAP HANA into R can be using a table typed user-defined function (UDF) instead. The main difference here is that the calling statement is a simple SELECT and the result is simply the resultset of this SELECT.
CREATE function "FGET_RECORDS" (IN id_list VARCHAR(4000))
returns tt_cusers
LANGUAGE SQLSCRIPT
SQL SECURITY INVOKER
READS SQL DATA AS
BEGIN
declare _filter VARCHAR(4000);
_users = select * from cusers;
-- APPLY_FILTER expects a proper WHERE condition, so adding the column to filter
-- and the IN () expression is necessary.
--
-- the the id_list comes in with single quotes, let's remove those
_filter = 'USER_ID in (' || replace (:id_list, '''', '') ||')';
_result = APPLY_FILTER(:_users, :_filter);
RETURN :_result;
end;
select * from fget_records (? );
In R (or in any other client) make sure to use bind variables when using this construct. Otherwise handling the different string quote-mechanisms can become cumbersome.
See the documentation on APPLY_FILTER here.

Answer 2

Use a User Defined Data Type.
First Create A User Defined Data Type
Database Node > Programmability > Types > User-Defined Table Types
Script :
CREATE TYPE dbo.MyTableType AS TABLE
(
ID INT
)
Create a Parameter in your procedure with the above type
CREATE PROCEDURE usp_InsertMessages
(
#MyParameter MyTableType READONLY
)
AS
BEGIN
INSERT INTO MyTable
(
id
)
SELECT
id
FROM #MyParameter
END