RE: Re: 7.1.2 ERROR: UNIQUE constraint matching given keys for referenced table ...... - Mailing list pgsql-general

Thanks your reply.

Actully, We are using 4 fields (CompanySerialNo, BrahcnOffice, DepartmentCategory, Department) to check employee work
forwhich company parimary. Well, we have many company here (In Taiwan) have multi-company name but in same office. Some
employeework for all multi-company. But our system only allow one employee belong to one company in this time. 

Create Table CompanyInfo
(
    CompanySerialNo    Char(20)    Parimary Key,
    LocalName        Text,
    EnglishName        Text,
    .............................
    .............................
);

Create Table DepartmentInfo
(
    CompanySerialNo    Char(20)    References CompanyInfo
                        On Update Cascade
                        On Delete Cascade,
    BranchOffice        Char(40) Default '',
    DepartmentCategory    Char(40) Default '',
    Department        Char(40) Default ''
    /* Primary Key (CompanySerialNo, BranchOffice, DepartmentCategory, Department)    */
);

Create Table EmployeeInfo
(
    EmployeeNo        Char(20)    Primary Key,
    LocalName        Text,
    FirstName        Text,
    LastName        Text,
    ...........................
    ...........................
    CompanySerialNo    Char(20)    References CompanyInfo
                        On Update Cascade
                        On Delete Cascade,
    BranchOffice        Char(40),    /* References DepartmentInfo (BranchOffice)    */
                        /* On Update Cascade                */
                        /* On Delete Set Default,                */
    DepartmentCategory    Char(40),    /* References DepartmentInfo (DepartmentCategory)*/
                        /* On Update Cascade                */
                        /* On Delete Set Default,                */
    Department        Char(40),    /* References DepartmentInfo (Department)        */
                        /* On Update Cascade                */
                        /* On Delete Set Default,                */
    ...........................
    ...........................
);

    If

    1.    one company don't allow multi-department with same name

        How to set the references in EmployeeInfo table ?

    2.    one company allow multi-department with same name (But not with same BranchOffice and/or DepartmentCategory).

        How to set the references in EmployeeInfo table ?

    without to using trigger (if possible).

    I think the postgresql from 7.0.3 to 7.1.2 have change some basic rule. The old code work fine in 7.0.3 but not ok
in7.1.2. 



-----Original Message-----
From: Stephan Szabo [mailto:sszabo@megazone23.bigpanda.com]
Sent: Wednesday, July 04, 2001 8:17 AM
To: Lincy
Cc: pgsql-general@postgresql.org
Subject: Re: [GENERAL] Re: 7.1.2 ERROR: UNIQUE constraint matching given keys for referenced table ......


On Tue, 26 Jun 2001, Lincy wrote:

> Ljb :
>
>     Thanks your help. Look like add the UNIQUE constraint on it can solve
> this problem. Now I know what the problem is. But since our system must
> handle multi-company in same time. So we can't let department to be UNIQUE.
> What we try to using references in EmployeeInfo are just for check the
> department was exist or not. So, we will try to using trigger to do this
> check. Well, if need to write our own trigger for each table, we have lots
> work to do.   :(

If department can't be unique (presumably because two companies could have
the same department name) then wouldn't you want to know what company the
employee and department belong to?  If so, then the key should be both the
company and department (unless you're allowing one company to have
multiple departments of the same name) which would then be legally unique
and referenceable.