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8.2

Help with Oracle SQL* PLUS Query. Self referential join

Asked by colivet in Oracle 10.x, PL / SQL, Oracle Database

Tags: oracle, self, join, referential, sql

I am trying to perform a self referential join in SQL (on Oracle but any ANSI compliant code will do).
I want the "superssn" foreign key in the employee table to reference the "ssn" primary key in the employee table.

I create the table as follows:
Create table employee
      (name VARCHAR2(40) NOT NULL,
      ssn VARCHAR2(10) PRIMARY KEY,
      bdate DATE NOT NULL,
      sex VARCHAR(1) NOT NULL,
      salary NUMBER(5),
      superssn VARCHAR2(10),
      dno VARCHAR2(2)
      );

I then add the contraints as follows:

ALTER TABLE employee
ADD CONSTRAINT employee_superssn_fk FOREIGN KEY (superssn) REFERENCES employee(ssn) INITIALLY DEFERRED DEFERRABLE ;

When I try to insert values into the table as follows:

insert into employee values (
'John L Hooker','123456789','09-JAN-55','M',30000,'333445555','5');

I get the following error message:
ORA-02091: transaction rolled back
ORA-02091: integrity constraint (SYSTEM.EMPLOYEE_DNO_FK) violated - parent key not found.

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Help with Oracle SQL* PLUS Query. Self referential join

Asked by colivet in Oracle 10.x, PL / SQL, Oracle Database

Tags: oracle, self, join, referential, sql

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