# DB synchro suspect behavior
**URL:** https://discuss.tryton.org/t/db-synchro-suspect-behavior/7052
**Category:** Developer
**Created:** [March 5, 2024, 10:05am UTC](https://discuss.tryton.org/t/db-synchro-suspect-behavior/7052 "2024-03-05T10:05:06Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@lb1975](https://discuss.tryton.org/u/lb1975)
#### Post date: [March 5, 2024, 10:05am UTC](https://discuss.tryton.org/t/db-synchro-suspect-behavior/7052/1 "2024-03-05T10:05:06Z")
Hi,
Sometimes after a lot of new dev, the system asks me for required fields when I try to save but these fields are filled and the only way I can solve the problem is to restore a dump of the version of the db before the new dev (“trytond-admin -d tradon --all” has no effect).
So my question is what can I do to force the synchro between code and db without restoring all the db ?
Is there certain table to drop or cache somewhere to delete ?
The problem is on db side cause each time I restore it works without changing code.
KR,
Laurent
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### Author:  [@ced](https://discuss.tryton.org/u/ced)
#### Post date: [March 5, 2024, 10:43am UTC](https://discuss.tryton.org/t/db-synchro-suspect-behavior/7052/2 "2024-03-05T10:43:09Z")
Some database schema changes must be handled by the developer like removing a required on a field.
So such case must be managed explicitly in ` __register__ ` method using `TableHandler`.
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### Author:  [@lb1975](https://discuss.tryton.org/u/lb1975)
#### Post date: [March 5, 2024, 1:35pm UTC](https://discuss.tryton.org/t/db-synchro-suspect-behavior/7052/3 "2024-03-05T13:35:04Z")
We always have the choice between managing the changes in **register** or directly updated the db ?
I don’t find any required column in ir\_model\_field, where is it managed ?
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### Author:  [@ced](https://discuss.tryton.org/u/ced)
#### Post date: [March 5, 2024, 1:57pm UTC](https://discuss.tryton.org/t/db-synchro-suspect-behavior/7052/4 "2024-03-05T13:57:22Z")
A required is transformed in the database schema as `NOT NULL`.
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### Author:  [@lb1975](https://discuss.tryton.org/u/lb1975)
#### Post date: [March 5, 2024, 2:33pm UTC](https://discuss.tryton.org/t/db-synchro-suspect-behavior/7052/5 "2024-03-05T14:33:31Z")
oh yes sure tks Cédric