在更新表的主键字段或DELETE数据时，如果遇到ORA-02292: integrity constraint (xxxx) violated - child record found 这个是因为主外键关系，下面借助一个小列子来描述一下这个错误：
SQL> create table student
2 (
3 id number,
4 name nvarchar2(12),
5 constraint pk_student primary key(id)
6 );
Table created.
QL> create table grades
2 ( id number ,
3 subject nvarchar2(12),
4 scores number,
5 constraint pk_grades primary key(id ,subject),
6 constraint fk_student_id foreign key(id) references student(id)
7 );
Table created.
SQL> insert into student
2 values(1001,'kerry');
1 row created.
SQL> insert into student
2 values(1002,'jimmy');
1 row created.
SQL> commit;
Commit complete.
SQL> insert into grades
2 values(1001, 'math', 120);
1 row created.
SQL> insert into grades
2 values(1001, 'english', 106);
1 row created.
SQL> commit;
Commit complete.
SQL> update student set id=1004 where name='kerry';
update student set id=1004 where name='kerry'
*
ERROR at line 1:
ORA-02292: integrity constraint (TEST.FK_STUDENT_ID) violated - child record
found
SQL>