Re: Constraint already exists in Schema 'APP'

Hello John!
Constaint name must be unique at schema level (in your case APP schema). In
other words name for example first FK constaint as FK_PATIENT_PERSON_ID and
second as FK_EMPLOYEE_PERSON_ID (FK_table_referencingColumn).

Hope that helps!
Libor

2012/4/4 John Steele <[EMAIL PROTECTED]>

>
> I have three tables Person, Patient, and Employee. Both Patient and
> Employee
> have a Foreign Key to Person; however, when creating the constraint for the
> second time I get the following error:
>
> Constraint 'PERSON_FK' already exists in Schema 'APP'.
>
> [code]
> CREATE TABLE PERSON (
>        PERSON_ID INTEGER NOT NULL GENERATED ALWAYS AS IDENTITY (START WITH
> 1,
> INCREMENT BY 1)
> );
>
> CREATE TABLE PATIENT (
>        PATIENT_ID INTEGER NOT NULL GENERATED ALWAYS AS IDENTITY (START
> WITH 1,
> INCREMENT BY 1),
>        PERSON_ID INTEGER NOT NULL
> );
>
> ALTER TABLE PATIENT
>        ADD CONSTRAINT PERSON_FK Foreign Key (
>                PERSON_ID)
>        REFERENCES PERSON (
>                PERSON_ID);
>
>
> CREATE TABLE EMPLOYEE (
>        EMPLOYEE_ID INTEGER NOT NULL GENERATED ALWAYS AS IDENTITY (START
> WITH 1,
> INCREMENT BY 1),
>        PERSON_ID INTEGER NOT NULL
> );
>
> ALTER TABLE EMPLOYEE
>        ADD CONSTRAINT PERSON_FK Foreign Key (
>                PERSON_ID)
>        REFERENCES PERSON (
>                PERSON_ID);
> [/code]
>
> What do you do in this situation? Do you only create on constraint and then
> reference it when using it again? If so, how?
>
> Thanks,
> John Steele
>
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>
>