Sujet : Re: The joy of SQL
De : ldo (at) *nospam* nz.invalid (Lawrence D'Oliveiro)
Groupes : comp.os.linux.miscDate : 04. Nov 2024, 00:30:35
Autres entêtes
Organisation : A noiseless patient Spider
Message-ID : <vg912r$j4vj$4@dont-email.me>
References : 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
User-Agent : Pan/0.160 (Toresk; )
On Sat, 2 Nov 2024 21:48:47 -0400,
186282@ud0s4.net wrote:
MV = Multi-Valued = Data fields that can hold long lists of that KIND
of information. If you have a fleet-tracking DB then there'd be ONE
field saying "mileage" and likely another for "fuel-added" and they'd
just be added-to over time.
That’s just a single total in each field.
The record for that vehicle is read all-at-once, rather than there
being dozens, hundreds, of records for said vehicle every time it
was fueled-up.
This is why you have joins: so that you can retrieve multiple related
records with a single query. This is the proper relational way of doing
it.
Re: The joy of SQL
Re: The joy of SQL