ORA-02291: integrity constraint (string.string) violated – parent key not found

I got ” ORA-02291: integrity constraint (string.string) violated – parent key not found ” error in Oracle database.

 

ORA-02291: integrity constraint (string.string) violated – parent key not found

 

Details of error are as follows.

ORA-02291: integrity constraint (string.string) violated - parent key not found

Cause: A foreign key value has no matching primary key value.

Action: Delete the foreign key or add a matching primary key.


 

 

integrity constraint (string.string) violated – parent key not found

This ORA-02291 errors are related with the foreign key value has no matching primary key value.

To solve this error, you need to drop the foreign key or add a matching primary key.

Or firstly you need to insert the same value into the parent table, then you can insert the value into child table.

For example; I have 2 table which has relation between two table with EMPLOYEE_ID column as follows.

 

CREATE TABLE EMPLOYEE
( EMPLOYEE_ID numeric(10) not null,
NAME varchar2(50) not null,
LAST_NAME varchar2(50),
CONSTRAINT emp_pk PRIMARY KEY (EMPLOYEE_ID)
);

CREATE TABLE MANAGER
( ID numeric(10) not null,
EMPLOYEE_ID numeric(10) not null,
CONSTRAINT fk_EMPLOYEE
FOREIGN KEY (EMPLOYEE_ID)
REFERENCES EMPLOYEE (EMPLOYEE_ID)
);

 

I have inserted the following record.

INSERT INTO MANAGER (ID, EMPLOYEE_ID) VALUES (10, 63);

 

But I got this error, because 63 employee_id doesn’t exist in the employee table. So You need to insert this record to parent table, then you can insert the child table as follows.

 

INSERT INTO EMPLOYEE (EMPLOYEE_ID, NAME, LAST_NAME) VALUES (63, 'Mehmet ', 'Deveci ');

Then you can insert into the MANAGER table:

INSERT INTO MANAGER (ID, EMPLOYEE_ID) VALUES (10, 63);

 

Or you need to drop the emp_pk constraint.

 

 

Do you want to learn Oracle Database for Beginners, then read the following articles.

Oracle Tutorial | Oracle Database Tutorials for Beginners ( Junior Oracle DBA )

 

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About Mehmet Salih Deveci

I am Founder of SysDBASoft IT and IT Tutorial and Certified Expert about Oracle & SQL Server database, Goldengate, Exadata Machine, Oracle Database Appliance administrator with 10+years experience.I have OCA, OCP, OCE RAC Expert Certificates I have worked 100+ Banking, Insurance, Finance, Telco and etc. clients as a Consultant, Insource or Outsource.I have done 200+ Operations in this clients such as Exadata Installation & PoC & Migration & Upgrade, Oracle & SQL Server Database Upgrade, Oracle RAC Installation, SQL Server AlwaysOn Installation, Database Migration, Disaster Recovery, Backup Restore, Performance Tuning, Periodic Healthchecks.I have done 2000+ Table replication with Goldengate or SQL Server Replication tool for DWH Databases in many clients.If you need Oracle DBA, SQL Server DBA, APPS DBA,  Exadata, Goldengate, EBS Consultancy and Training you can send my email adress [email protected].-                                                                                                                                                                                                                                                 -Oracle DBA, SQL Server DBA, APPS DBA,  Exadata, Goldengate, EBS ve linux Danışmanlık ve Eğitim için  [email protected] a mail atabilirsiniz.

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