SAP DBTech JDBC: [359]: string is too long [359] (range 3) string is too long exception

I am getting following error when I call my stored proc. I made changes to the datatype but not helping much. The goal is to create a big long SQL on the fly joining 19 tables.

I am getting following error

Here is the stored Proc

createprocedure sapecd.dynamic_tables() language sqlscript as

ctr integer;

vl_cnt integer;

sql_query_union nvarchar(5000);

v2 nvarchar(500);

begin

ctr:=1;

sql_query_union:='';

selectcount(*) into vl_cnt FROM TABLES WHERE schema_name like'SAPEC%'AND table_name like'/1FC/0ZSSM47A%';

WHILE ctr < :vl_cnt DO

select sqlquery into v2 from (

SELECT table_name,schema_name, '(select * from ' || schema_name || '."' || table_name || '")'as sqlquery, row_number() over (orderby table_name) as row_num FROM TABLES

WHERE schema_name like'SAPEC%'AND table_name like'/1FC/0ZSSM47A%') where row_num=:ctr;

sql_query_union := sql_query_union || v2 || ' union all ';

ctr:=ctr+1;

ENDWHILE;

select sqlquery into v2 from (

SELECT table_name,schema_name, 'select * from ' || schema_name || '."' || table_name || '"'as sqlquery, row_number() over (orderby table_name) as row_num FROM TABLES

WHERE schema_name like'SAPEC%'AND table_name like'/1FC/0ZSSM47A%') where row_num=:vl_cnt;

-- sql_query_union := sql_query_union || v2;

sql_query_union := v2;

EXEC sql_query_union;

end