Search notes:

ORA-02273: this unique/primary key is referenced by some foreign keys

A primary key cannot be dropped as long as foreign keys reference it. An attempt to do so results in the error message ORA-02273: this unique/primary key is referenced by some foreign keys.

This is demonstrated with the following simple snippets.

Create two tables with a primary key-foreign key relation:

create table tq84_P (
    id  integer,
    txt varchar2(10) not null,
    constraint tq84_P_pk primary key (id)
);

create table tq84_C (
    id_p   not null,
    val    number(5,2),
    constraint tq84_C_fk foreign key (id_p) references tq84_P
);

The following statement throws ORA-02273: this unique/primary key is referenced by some foreign keys:

alter table tq84_P drop constraint tq84_P_pk;

Cleaning up:

drop table tq84_C;
drop table tq84_P;

Fatal error: Uncaught PDOException: SQLSTATE[HY000]: General error: 8 attempt to write a readonly database in /home/httpd/vhosts/renenyffenegger.ch/php/web-request-database.php:78 Stack trace: #0 /home/httpd/vhosts/renenyffenegger.ch/php/web-request-database.php(78): PDOStatement->execute(Array) #1 /home/httpd/vhosts/renenyffenegger.ch/php/web-request-database.php(30): insert_webrequest_('/notes/developm...', 1759421861, '216.73.216.42', 'Mozilla/5.0 App...', NULL) #2 /home/httpd/vhosts/renenyffenegger.ch/httpsdocs/notes/development/databases/Oracle/errors/ORA-02273_this-unique_primary-key-is-referenced-by-some-foreign-keys(65): insert_webrequest() #3 {main} thrown in /home/httpd/vhosts/renenyffenegger.ch/php/web-request-database.php on line 78

ORA-02273: this unique/primary key is referenced by some foreign keys

See also