Spencer Simpson wrote:
No, I've found that aliases (especially objects) can act strangely if you
try to extract their values more than once between two successive fetches.
Maybe newer versions of MapInfo are more robust, but it conditioned me to
always fetch aliases into variables back in the 1990s.
I'd have to say, "Prove it." IMHO, that's a superstition that you
develpoed as you were learning and now it's just a habit. It's similar
to the superstition that using defined constants is not safe.
Using "degenerate" objects to simulate null objects is useful, but it
doesn't help fetching them from a table, because you can't guarantee that a
row didn't have its object deleted.
That's right. And for that you can test the object itself (which is
actually an alias). But once you put an object into a variable you need
another way to indicate whether its valid or not.
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