row dependencies

#1

I was just wondering if you can have a situation in databases where
row B depends on row A, and row A depends on row B. Is this a sign of
bad design if you have this?

And, can someone give me a concrete example of when you might have
this in the real world?

#2

On Jul 12, 12:03 am, b... (AT) coolgroups (DOT) com wrote:

Quote:

I was just wondering if you can have a situation in databases where
row B depends on row A, and row A depends on row B. Is this a sign of
bad design if you have this?

And, can someone give me a concrete example of when you might have
this in the real world?

An employee table often includes a manager attribute where a manager
must be an employee. I cannot think immediately of one going both ways
in the same table. What leads you to ask this?

Ed

#3

Ed Prochak <edprochak (AT) gmail (DOT) com> wrote:

Quote:

On Jul 12, 12:03 am, b... (AT) coolgroups (DOT) com wrote:
I was just wondering if you can have a situation in databases where
row B depends on row A, and row A depends on row B. Is this a sign of
bad design if you have this?

And, can someone give me a concrete example of when you might have
this in the real world?

An employee table often includes a manager attribute where a manager
must be an employee. I cannot think immediately of one going both ways
in the same table. What leads you to ask this?

This example would be better split into two tables (employee and
employee's manager). At least one employee is not going to have a
manager.

Sincerely,

Gene Wirchenko

Computerese Irregular Verb Conjugation:
I have preferences.
You have biases.
He/She has prejudices.

#4

Ed Prochak wrote:

Quote:

On Jul 12, 12:03 am, b... (AT) coolgroups (DOT) com wrote:

I was just wondering if you can have a situation in databases where
row B depends on row A, and row A depends on row B. Is this a sign of
bad design if you have this?

And, can someone give me a concrete example of when you might have
this in the real world?

An employee table often includes a manager attribute where a manager
must be an employee. I cannot think immediately of one going both ways
in the same table. ...

Spouses?

#5

On Jul 12, 3:21 pm, paul c <toledobythe... (AT) oohay (DOT) ac> wrote:

Quote:

Ed Prochak wrote:
On Jul 12, 12:03 am, b... (AT) coolgroups (DOT) com wrote:

I was just wondering if you can have a situation in databases where
row B depends on row A, and row A depends on row B. Is this a sign of
bad design if you have this?

And, can someone give me a concrete example of when you might have
this in the real world?

An employee table often includes a manager attribute where a manager
must be an employee. I cannot think immediately of one going both ways
in the same table. ...

Spouses?

ooo, you're good! nice example.

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row dependencies

comp.databases comp.databases

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