Oracle 18c

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select * from V$VERSION;


BANNER
BANNER_FULL
BANNER_LEGACY
CON_ID


Oracle Database 18c Express Edition Release 18.0.0.0.0 - Production
Oracle Database 18c Express Edition Release 18.0.0.0.0 - Production
Version 18.4.0.0.0
Oracle Database 18c Express Edition Release 18.0.0.0.0 - Production
0


create table tab (
    id int generated always as identity primary key,
    col1 varchar2 (16),
    col2 number)
insert into tab (col1, col2) 
    select trim (column_value), rownum from xmlTable ('"a","b","c"')
3 rows affected

select * from tab


ID
COL1
COL2


1
a
1

2
b
2

3
c
3


create or replace package tabapi as
    type rec is record (
        rid varchar2 (18), col1 varchar2 (32), col2 number); 
    type arr is table of rec;
    procedure assert (t arr);     
end;
/
create or replace package body tabapi as
    procedure assert (t arr) is 
    begin 
        for r in (
            select t.*
            from table (t) t 
            join tab t1 on t1.col1 = t.col1 and t1.rowid != chartorowid (t.rid) 
            join tab t2 on t2.col2 = t.col2 and t2.rowid != chartorowid (t.rid)
            fetch first 1 row only
        ) loop raise_application_error (-20000, 'Found cross row duplicates ('||r.col1||','||r.col2||')');
         end loop;   
    end; 
end;
/
create or replace trigger trigTabCheckCrossRowDuplicates 
for update or insert on tab compound trigger
    rows tabapi.arr := tabapi.arr ();
    after each row is    
    begin
        rows.extend;
        rows (rows.count) := tabapi.rec (
            rowidtochar (:new.rowid), :new.col1, :new.col2);
    end after each row;
    after statement is
    begin
        tabapi.assert (rows);
    end after statement;    
end;
/
insert into tab (col1, col2) values ('a', 4);
1 rows affected

insert into tab (col1, col2) values ('c', 1);
ORA-20000: Found cross row duplicates (c,1)
ORA-06512: at "FIDDLE_WTCMMTLUNCGCVFODTNCZ.TABAPI", line 10
ORA-06512: at "FIDDLE_WTCMMTLUNCGCVFODTNCZ.TABAPI", line 10
ORA-06512: at "FIDDLE_WTCMMTLUNCGCVFODTNCZ.TRIGTABCHECKCROSSROWDUPLICATES", line 11
ORA-04088: error during execution of trigger 'FIDDLE_WTCMMTLUNCGCVFODTNCZ.TRIGTABCHECKCROSSROWDUPLICATES'