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From: JORGE MALDONADO <jorgemal1960@gmail.com>
Date: Wed, 1 May 2024 18:08:33 -0500
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 <CAAY=A79usb2Lbr9nUyzxyRNWLQNc-w3oTBbtUGyC2a4E-qaX3A@mail.gmail.com>
Subject: One parent record with 3 possible child records
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Hi,

I have one table that can have relations to only 1 of 3 possible tables.
For example: tblMain*,* tblOne, tblTwo and tblThree.

I will always have 1 record in tblMain but each record in this table will
be related to one record in tblOne OR one record in tblTwo OR one record in
tblThree.

The relation between tblMain and tblOne is 1:1.
The relation between tblMain and tblTwo is 1:1.
The relation between tblMain and tblThree is 1:1.

Is it better to set tblMain as parent or child?

This can be seen as if tblOne, tblTwo and tblThree
extend tblMain depending on a specific criteria.

Let's say that tableMain has a string field called "type" with the
following possible values: "residential", "industrial" and "energy".

I will always insert a record in tblMain but:
* If type is "residential" then a record in tblOne is created and it is
associated to tblMain,
* If type is "industrial" a record in tblTwo is created and it is
associated to tblMain
* If type is "energy" a record in tblThree is created and it is associated
to tblMain.

I am not sure how to design a case like this. I will very much appreciate
your feedback.

Best regards,
Jorge Maldonado

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<div dir=3D"ltr"><div dir=3D"ltr"><div dir=3D"ltr">Hi,<div><br></div><div>I=
 have one table that can have relations to only 1 of 3 possible tables. For=
 example:=C2=A0tblMain<b>,</b>=C2=A0tblOne, tblTwo and tblThree.=C2=A0</div=
><div><br></div><div>I will always have 1 record in tblMain=C2=A0but each r=
ecord in this table will be related to one record in tblOne OR one record i=
n tblTwo OR one record in tblThree.=C2=A0</div><div><br></div><div>The rela=
tion between tblMain=C2=A0and tblOne is 1:1.</div><div>The relation between=
 tblMain=C2=A0and tblTwo is 1:1.</div><div>The relation between tblMain=C2=
=A0and tblThree is 1:1.</div><div><br></div><div>Is it better to set tblMai=
n=C2=A0as parent or child?</div><div><br></div><div>This can be seen as if =
tblOne, tblTwo and tblThree extend=C2=A0tblMain=C2=A0depending=C2=A0on a sp=
ecific criteria.<br></div><div><br></div><div>Let&#39;s say that tableMain =
has a string field called &quot;type&quot; with the following possible valu=
es: &quot;residential&quot;, &quot;industrial&quot; and &quot;energy&quot;.=
=C2=A0</div><div><br></div><div>I will always insert a record in tblMain bu=
t:</div><div>* If type is &quot;residential&quot; then a record in tblOne i=
s created and it is associated to tblMain,=C2=A0</div><div>* If type is &qu=
ot;industrial&quot; a record in tblTwo is created and it is associated to t=
blMain</div><div>* If type is &quot;energy&quot; a record in tblThree=C2=A0=
is created=C2=A0and it is associated to tblMain.</div><div><br></div><div>I=
 am not sure how to design a case like this. I will very much appreciate yo=
ur feedback.</div><div><br></div><div>Best regards,</div><div>Jorge Maldona=
do</div><div><br></div></div></div></div>

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