Problem with Zeos 7 beta
lazarus / 16-Databases

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Blestan · 2012-12-14 16:05

Hi all!
i have the folowing situation :
i have a zquery with sql that involves 2-3 tables left joined...
the query is NOT readonly but i get error when i try to update the
main table ... i.e the zquery becomes readonly and i receive

Readonly field can't be assigned a value ....

any ideas why or how to bypass this problem?

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bobo · 2012-12-14 18:32

You should post this on the ZEOS forums, but include more info about
OS/Lazarus/fpc versions and maybe a code snippet or example program.

http://zeos.firmos.at/index.php

and go to the "Zeoslib 7.0 Betatest Forum".

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EgonHugeist · 2012-12-14 22:42

The reason is quiet simple:

Zeos is able to determine default-values, not-null fields etc..

Now you use some joins with some more tybles and each check of
metainformations will fail. Zeos is able to read the metainformations
of one table but joins can be very complex and Zeos determines the
Field-Names,Types from ResultSet informations the Drivers do return.
but these informations do not tell Zeos if a field is Writeable or
not...

So you won't be able to update a complex query in your custom way. You
need the TZUpdateSQL Component for this case. Then it's on you to tell
Zeos which field can be written and how.

Best regards, Michael