Слияние дубликатов в Oracle

create table city (   id          number                            not null,   name        varchar2(30)                      not null );  create unique index city_pk on city(id);  alter table city   add constraint city_pk primary key(id);   create table street (   id          number                            not null,   city_id     number                            not null,   name        varchar2(30)                      not null );  create unique index street_pk on street(id);  create index street_fk on street(city_id);  alter table street   add constraint street_pk primary key(id);   alter table street add   constraint fk_street foreign key (city_id)      references city(id);  create table address (   id          number                            not null,   street_id   number                            not null,   house       varchar2(10)                      not null,   apartment  varchar2(10) );  create unique index address_pk on address(id);  create index address_fk on address(street_id);  alter table address   add constraint address_pk primary key(id);   alter table address add   constraint fk_address foreign key (street_id)      references street(id); 

insert into city(id, name) values (1, 'Казань');  insert into street(id, city_id, name) values (1, 1, 'Победы'); insert into street(id, city_id, name) values (2, 1, 'Победы проспект');  insert into address(id, street_id, house, apartment) values (1, 1, '10', '1'); insert into address(id, street_id, house, apartment) values (2, 2, '10', '2'); 

create table mg_table (   name        varchar2(30)                      not null );  create unique index mg_table_pk on mg_table(name);  alter table mg_table   add constraint mg_table_pk primary key(name);   create sequence mg_merge_seq;  create table mg_merge (   id          number                            not null,   table_name  varchar2(30)                      not null,   old_id      number                            not null,   new_id      number                            not null );  create unique index mg_merge_pk on mg_merge(id);  create unique index mg_merge_uk on mg_merge(table_name, old_id);  alter table mg_merge   add constraint mg_merge_pk primary key(id);   alter table mg_merge add   constraint fk_mg_merge foreign key (table_name)      references mg_table(name);  create sequence mg_ref_seq;  create table mg_ref (   id          number                            not null,   merge_id    number                            not null,   table_name  varchar2(30)                      not null,   pk_name     varchar2(30)                      not null,   column_name varchar2(30)                      not null,   object_id   number                            not null );  create unique index mg_ref_pk on mg_ref(id);  create index mg_ref_fk on mg_ref(merge_id);  alter table mg_ref   add constraint mg_ref_pk primary key(id);   alter table mg_ref add   constraint fk_mg_ref foreign key (merge_id)      references mg_merge(id); 

create or replace package mg_merge_pkg as     procedure merge(p_name in varchar2, p_old in number, p_new in number);     procedure undo(p_id in number);     procedure undo; end mg_merge_pkg; /  show errors;  create or replace package body mg_merge_pkg as      e_unsupported_error EXCEPTION;     pragma EXCEPTION_INIT(e_unsupported_error, -20001);      cursor c_col(p_name varchar2, p_pk varchar2) is     select column_name     from   user_tab_columns     where  table_name = upper(p_name)     and    column_name <> p_pk;      procedure merge(p_name in varchar2, p_old in number, p_new in number) as     cursor c_fk is     select b.table_name, c.column_name, e.column_name pk_name     from   user_constraints a     inner  join user_constraints b on (b.r_constraint_name = a.constraint_name)     inner  join user_cons_columns c on (c.constraint_name = b.constraint_name)     inner  join user_constraints d on (d.table_name = b.table_name                                          and d.constraint_type = 'P')     inner  join user_cons_columns e on (e.constraint_name = d.constraint_name)     where  a.table_name = upper(p_name);     r_fk   c_fk%rowtype;     r_col  c_col%rowtype;     l_id   number default null;     l_cn   number default null;     l_pk   varchar2(30) default null;     l_sql  varchar2(500) default null;     begin       select max(cn) into l_cn       from ( select b.constraint_name, count(*) cn              from   user_constraints a              inner  join user_constraints b on (b.r_constraint_name = a.constraint_name)              inner  join user_cons_columns c on (c.constraint_name = b.constraint_name)              where  a.table_name = upper(p_name)              group  by b.constraint_name );       if l_cn > 1 then          RAISE_APPLICATION_ERROR(-20001, 'Can''t support multicolumn FK');       end if;              select c.column_name into l_pk       from   user_constraints a       inner  join user_cons_columns c on (c.constraint_name = a.constraint_name)       where  a.table_name = upper(p_name)       and    a.constraint_type = 'P';              select count(*) into l_cn       from   mg_table where name = upper(p_name);       if l_cn = 0 then          insert into mg_table(name) values (upper(p_name));          execute immediate         'create table mg_' || p_name || ' as select * from ' || upper(p_name) || ' ' ||         'where rownum = 0';          execute immediate         'create unique index mg_' || p_name || '_pk on mg_' || p_name || '(' || l_pk || ')';       end if;              insert into mg_merge(id, table_name, old_id, new_id)       values (mg_merge_seq.nextval, upper(p_name), p_old, p_new)       returning id into l_id;               open c_fk;       loop         fetch c_fk into r_fk;         exit when c_fk%notfound;                  execute immediate        'insert into mg_ref(id, merge_id, table_name, pk_name, column_name, object_id) ' ||        'select mg_ref_seq.nextval, :merge_id, :tab_name, :pk_name, :col_name, ' || r_fk.pk_name || ' ' ||        'from   ' || r_fk.table_name || ' where ' || r_fk.column_name || ' = :old_id'          using l_id, r_fk.table_name, r_fk.pk_name, r_fk.column_name, p_old;                  execute immediate        'update ' || r_fk.table_name || ' set ' || r_fk.column_name || ' = :new_id ' ||        'where ' || r_fk.column_name || ' = :old_id' using p_new, p_old;       end loop;       close c_fk;              l_sql := 'insert into mg_' || p_name || '(' || l_pk;       open c_col(p_name, l_pk);       loop         fetch c_col into r_col;         exit when c_col%notfound;         l_sql := l_sql || ',' || r_col.column_name;       end loop;       close c_col;       l_sql := l_sql || ') select '|| l_pk;       open c_col(p_name, l_pk);       loop         fetch c_col into r_col;         exit when c_col%notfound;         l_sql := l_sql || ',' || r_col.column_name;       end loop;       close c_col;       l_sql := l_sql || ' from ' || p_name || ' where ' || l_pk || ' = :old_id';       execute immediate l_sql using p_old;              execute immediate      'delete from ' || p_name || ' where ' || l_pk || ' = :id' using p_old;       commit;     exception       when others then         if c_fk%isopen then close c_fk; end if;         if c_col%isopen then close c_col; end if;         rollback;         raise;     end;      procedure undo(p_id in number) as     cursor c_fk is     select table_name, pk_name, column_name     from   mg_ref     where  merge_id = p_id     group  by table_name, pk_name, column_name;     r_fk   c_fk%rowtype;     r_col  c_col%rowtype;     l_name varchar2(30) default null;     l_old  number default null;     l_new  number default null;     l_cn   number default null;     l_pk   varchar2(30) default null;     l_sql  varchar2(500) default null;     begin       select table_name, old_id, new_id into l_name, l_old, l_new       from   mg_merge where id = p_id;              select count(*) into l_cn       from   mg_merge where old_id = l_new;       if l_cn > 0 then          RAISE_APPLICATION_ERROR(-20001, 'Can''t undo');       end if;              select c.column_name into l_pk       from   user_constraints a       inner  join user_cons_columns c on (c.constraint_name = a.constraint_name)       where  a.table_name = upper(l_name)       and    a.constraint_type = 'P';        l_sql := 'insert into ' || l_name || '(' || l_pk;       open c_col(l_name, l_pk);       loop         fetch c_col into r_col;         exit when c_col%notfound;         l_sql := l_sql || ',' || r_col.column_name;       end loop;       close c_col;       l_sql := l_sql || ') select '|| l_pk;       open c_col(l_name, l_pk);       loop         fetch c_col into r_col;         exit when c_col%notfound;         l_sql := l_sql || ',' || r_col.column_name;       end loop;       close c_col;       l_sql := l_sql || ' from mg_' || l_name || ' where ' || l_pk || ' = :old_id';       execute immediate l_sql using l_old;              open c_fk;       loop         fetch c_fk into r_fk;         exit when c_fk%notfound;                  execute immediate        'merge into ' || r_fk.table_name || ' d using mg_ref s '||        'on (s.object_id = d.' || r_fk.pk_name || ' and s.merge_id = :id and s.table_name = :tab_name and s.column_name = :col_name) ' ||        'when matched then ' ||        'update set d.' || r_fk.column_name || ' = :old_id' using p_id, r_fk.table_name, r_fk.column_name, l_old;        end loop;       close c_fk;              execute immediate      'delete from mg_' || l_name || ' where ' || l_pk || ' = :id' using l_old;               delete from mg_ref where merge_id = p_id;       delete from mg_merge where id = p_id;        commit;     exception       when others then         if c_fk%isopen then close c_fk; end if;         if c_col%isopen then close c_col; end if;         rollback;         raise;     end;      procedure undo as     l_id number default null;     begin       select max(id) into l_id from mg_merge;       undo(l_id);     end; end mg_merge_pkg; /  show errors;