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From: Ron Johnson <ronljohnsonjr@gmail.com>
Date: Wed, 22 Jan 2025 10:15:04 -0500
Message-ID: <CANzqJaBvJ=jXKuyahznN3_GrT0gAdw+r_+xSOd7P72EVufMvSw@mail.gmail.com>
Subject: Re: Automatic deletion of orphaned rows
To: "pgsql-generallists.postgresql.org" <pgsql-general@lists.postgresql.org>
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On Wed, Jan 22, 2025 at 9:37=E2=80=AFAM David G. Johnston <
david.g.johnston@gmail.com> wrote:

> On Wednesday, January 22, 2025, Ron Johnson <ronljohnsonjr@gmail.com>
> wrote:
>>
>>
>>> I therefore propose a feature, to be able to specify in a table schema
>>> that a row should be deleted if orphaned.
>>
>>
>> For one thing, rows *can't* be orphaned if there's a foreign key
>> reference.
>>
>
> The description was correct even though using probably imprecise
> terminology.  The basic goal is to delete childless parents.
>

That's kinda what I thought he wrote, but it's so far beyond "normal" that
I dismissed the possibility.  Parents are allowed to not have
children, after all.

Is there *ANY* DBMS with a built-in reverse FK "parents must have children"
feature?

--=20
Death to <Redacted>, and butter sauce.
Don't boil me, I'm still alive.
<Redacted> lobster!

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<div dir=3D"ltr"><div dir=3D"ltr">On Wed, Jan 22, 2025 at 9:37=E2=80=AFAM D=
avid G. Johnston &lt;<a href=3D"mailto:david.g.johnston@gmail.com">david.g.=
johnston@gmail.com</a>&gt; wrote:</div><div class=3D"gmail_quote gmail_quot=
e_container"><blockquote class=3D"gmail_quote" style=3D"margin:0px 0px 0px =
0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">On Wednesday=
, January 22, 2025, Ron Johnson &lt;<a href=3D"mailto:ronljohnsonjr@gmail.c=
om" target=3D"_blank">ronljohnsonjr@gmail.com</a>&gt; wrote:<blockquote cla=
ss=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-left:1px solid =
rgb(204,204,204);padding-left:1ex"><div dir=3D"ltr"><div class=3D"gmail_quo=
te"><blockquote class=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;bor=
der-left:1px solid rgb(204,204,204);padding-left:1ex">
<br>
I therefore propose a feature, to be able to specify in a table schema<br>
that a row should be deleted if orphaned.</blockquote><div><br></div><div>F=
or one thing, rows <b>can&#39;t</b>=C2=A0be orphaned if there&#39;s a forei=
gn key reference.=C2=A0</div></div></div></blockquote><div><br></div><div>T=
he description was correct even though using probably imprecise terminology=
.=C2=A0 The basic goal is to delete childless parents.</div></blockquote><d=
iv><br></div><div>That&#39;s=C2=A0kinda what I=C2=A0thought he=C2=A0wrote,=
=C2=A0but it&#39;s so far beyond &quot;normal&quot; that I dismissed=C2=A0t=
he=C2=A0possibility.=C2=A0 Parents are allowed to not have children,=C2=A0a=
fter all.</div><div><br></div><div>Is there <i>ANY</i>=C2=A0DBMS with a bui=
lt-in reverse FK &quot;parents must have children&quot; feature?</div></div=
><div><br></div><span class=3D"gmail_signature_prefix">-- </span><br><div d=
ir=3D"ltr" class=3D"gmail_signature"><div dir=3D"ltr">Death to &lt;Redacted=
&gt;, and butter sauce.<div>Don&#39;t boil me, I&#39;m still alive.<br><div=
><div>&lt;Redacted&gt; lobster!</div></div></div></div></div></div>

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