We have table 'CUSTOMER' in two different schema's. Both are not having any primary key and the column numbers in both table do not match(i.e schema1 table can have 97 column other schema table has 101).the column names are same which are present in both tables. My task is to compare these 2 tables.

Firstly, For this i have created function which will fetch common columns in both tables.

create or replace function getcolumn(scheam1 varchar2,table1 varchar2) return sys_refcursor
as lc_refcursor
begin open lc_refcursor for 
select c1.column_name from sys.all_tab_columns c1 inner join user_tab_columns c2 on c1.column_name=c2.column_name and c1.table_name=c2.table_name where c1.owner=scheam1 and c1.table_name=table1 ;
return lc_refcursor; 
end;

Then i would be calling this into a procedure , using this columnlist we can compare two tables. (I am hoping the algorithm is correct, if not please suggest algorithm to compare tables)

create or replace procedure comparetable( schema1 in varchar2,table1 in varchar2,schema2 in varchar2,table2 in varchar2, p_array_size in number default 100 )
 as l_cursor sys_refcursor; 
l_owner dbms_sql.varchar2_table;
l_object_name dbms_sql.varchar2_table; 
l_object_id dbms_sql.number_table;
l_created dbms_sql.date_table;
l_processed_cnt number := 0;
column_list varchar2(3000);begin
column_list := 'select * from getcolumn('||schema1||','||table1||'))';

 open l_cursor for 'select t1.* from (select distinct'||column_list||'from'||table1||')t1 where not exists(select 1 from'||schema2||'.'||table2||'t2 where (t1.'||column_list||'=t2.'||column_list||'or t1.||column_list||'is null and t2.'||column_list|| is null))';
 loop
 fetch l_cursor BULK COLLECT
 into l_owner, l_object_name, l_object_id, l_created
 LIMIT p_array_size;
 for i in 1 .. l_owner.count
 loop
 l_processed_cnt := l_processed_cnt+1;
 end loop;
 exit when l_cursor%notfound;
 end loop;
 close l_cursor;
 dbms_output.put_line( 'processed ' || l_processed_cnt || ' records' );
 end;

This procedure is giving error as missing expression at line 13.

Please help with the error and also the algorithm to compare tables depending on the record loaded date(i havent passed this input yet).

column_list := 'select * from getcolumn('||schema1||','||table1||'))';

create table t1 (
  c1 int,
  c2 int,
  c3 int
);
create table t2 (
  c2 int,
  c3 int,
  c4 int
);

with cols as ( 
  select column_name from user_tab_cols
  where  table_name = 'T1'
  intersect 
  select column_name from user_tab_cols
  where  table_name = 'T2'
)
  select listagg ( column_name, ',' ) 
           within group ( order by column_name )
  from   cols;

LISTAGG(COLUMN_NAME,',')WITHINGROUP(ORDERBYCOLUMN_NAME)   
C2,C3 

t1.'||column_list||'=t2.'||column_list