Null in SQL select union

Hi!

I want to execute two queries combined with UNION. In columns without a
value, I wand to have null for default. When sorting the resulting query,
rows with null in group-fields and a value in result-fields should be placed
after those with a value in group-fields.

Here is my example:

SELECT type, color, NULL AS number FROM cars
UNION SELECT NULL AS type, NULL AS color, COUNT(*) FROM cars
GROUP BY type
ORDER BY type, color

But this will not be executed because of errer "NULL is not a column of
cars".

How do I specify a null-value in a SELECT-clause?



Titus Kruse
Software-Entwicklung IBM iSeries
ESW Software Warda KG (GmbH & Co.)
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