Subject | |
---|---|
Author | Juarez Rudsatz |
Post date | 2001-02-10T14:26:24Z |
Some like this ?
UPDATE TableIWantUpdate
SET FieldIWant = ct.FieldIWant + at.AddedValue
FROM CopyofTableIWantUpdate ct , AnotherTable at
WHERE ct.KeyField = at.ForeignKey
I donĀ“t know how others dbms handle this, but copying syntax from another dbms will make user more comfortable when migrating to Firebird. Or not ?
--->
Relational theory tells us that you should never update
more than one column in any table with values from another
table (transitive dependency, I think). However, the
difference between theory and fact shows up in compound
primary keys (probably also theoretically unsound) and
other design compromises.
In short, being able to update from a select would be
a good thing.
Regards,
Ann
www.ibphoenix.com
We have answers.
<---
--
Auf Widersehen
Juarez Rudsatz
UPDATE TableIWantUpdate
SET FieldIWant = ct.FieldIWant + at.AddedValue
FROM CopyofTableIWantUpdate ct , AnotherTable at
WHERE ct.KeyField = at.ForeignKey
I donĀ“t know how others dbms handle this, but copying syntax from another dbms will make user more comfortable when migrating to Firebird. Or not ?
--->
Relational theory tells us that you should never update
more than one column in any table with values from another
table (transitive dependency, I think). However, the
difference between theory and fact shows up in compound
primary keys (probably also theoretically unsound) and
other design compromises.
In short, being able to update from a select would be
a good thing.
Regards,
Ann
www.ibphoenix.com
We have answers.
<---
--
Auf Widersehen
Juarez Rudsatz