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ey (id, name));
Table created.
SQL> create table t_c (id number, f_id number, f_name varchar2(30),
2 constraint fk_t_c foreign key (f_id, f_name) references t_p);
Table created.
SQL> insert into t_p values (1, 'a');
1 row created.
SQL> insert into t_c values (1, 1, 'a');
1 row created.
SQL> insert into t_c values (1, 1, 'b');
insert into t_c values (1, 1, 'b')
*
ERROR at line 1:
ORA-02291: integrity constraint (SCOTT.FK_T_C) violated - parent key not found
SQL> insert into t_c values (1, null, 'b');
1 row created.
SQL> insert into t_c values (1, null, 'b');
1 row created.
SQL> select * from t_c;
ID F_ID F_NAME
---------- ---------- ------------------------------
1 1 a
1 b
1 b
SQL>
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