Hi,

> Makes sense... kind of.
> IMHO the JOIN ON clause should be used only to define relation between
> tables. The TAB_Graafik.Kuupaev field isn't part of the relation, it's
> a part of the filter and thus belongs into WHERE. So in my head I
> "compiled" it like "no matching TAB_Graafik.Kuupaev for given month so
> it is NULL and OR(TAB_Graafik.Kuupaev IS NULL) takes care of it".
> Do other (major) RDBs work like FB in such a case? Or is this modus
> operandi even SQL standard?

Yes, other RDBMs work the same.
First you join all TAB_Graafik records based on UID.
There's at least 1 record in TAB_Graafik that can JOIN with TAB_Tooleping on UID = 2 (as you wrote
the relation between TAB_Graafik and TAB_Tooleping).
This meant there won't be NULLs for Kuupaev at time when the WHERE clause is evaluated, because
Kuupaev in your example will hold '2006-09-20'.

First the JOINs are made and second the WHERE clause is applied.

Regards,
Arno Brinkman
ABVisie

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