ok *click* i get it i get it
m
Oliver Elphick wrote:
>
> Murray Hobbs wrote:
> >
> >i neglected to show it properly
> >
> >have tables A, B, C, D PLUS a few others
> >
> >A <- B
> >
> > F
> > |
> > v
> >A <- C <- D
> > ^
> > |
> > E
> >
> >i want to delete from C and cascade any delete to E or F but not if
> >there are records in D
> >
> >what i have done is to have ON DELETE CASCADE on C's primary
> >
> >but force deletes to C through a function that will delete from C only
> >if there is no records in D
> >
> >but i would like to believe there is a better way - a way that does not
> >require that i do all my deletes through a function
>
> B REFERENCES A ON DELETE CASCADE
> C REFERENCES A ON DELETE CASCADE
> D REFERENCES C ON DELETE NO ACTION
> E REFERENCES C ON DELETE CASCADE
> F REFERENCES C ON DELETE CASCADE
>
> So if there is a deletion in A it cascades to B and C
>
> The deletion in C cascades to E and F, but fails if there is a
> reference in D. The failure causes a rollback of the transaction and
> thus the deletions in A, B, C, E and F do not happen after all.
>
> --
> Oliver Elphick Oliver.Elphick@lfix.co.uk
> Isle of Wight http://www.lfix.co.uk/oliver
> PGP: 1024R/32B8FAA1: 97 EA 1D 47 72 3F 28 47 6B 7E 39 CC 56 E4 C1 47
> GPG: 1024D/3E1D0C1C: CA12 09E0 E8D5 8870 5839 932A 614D 4C34 3E1D 0C1C
> ========================================
> "For God hath not appointed us to wrath, but to obtain
> salvation by our Lord Jesus Christ, Who died for us,
> that, whether we wake or sleep, we should live
> together with him."
> I Thessalonians 5:9,10
