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hello @bartlomiej.pobocha 

i need to know what is the diffrence between this two options and why i can't uncheck the option “Check_Approval”

Thanks for update.

We can see procedures belongs to database package PROJECT_TRANSACTION_API. Definition of all of them you can find in database in package body PROJECT_TRANSACTION_API. I guess the procedure “Check_Approve” is responsible for checking if project transaction can be approved and procedure “Add_Trans_To_Invoice__” is responsible for Add project Transaction To Invoice, but you need to confirm that by checking the mentioned package body.

What happening when you try to uncheck the option “Check_Approve”?

Thanks for the update.

We can see that the procedures belong to the database package PROJECT_TRANSACTION_API. Definitions of all of them can be found in the database in the PROJECT_TRANSACTION_API package body.

I'm guessing the "Check_Approve" procedure is responsible for checking if the project transaction can be approved and the "Add_Trans_To_Invoice__" procedure is responsible for adding the transaction to the project invoice or adding project transaction to the invoice(probably the second one), but you need to confirm this by checking the package body mentioned.

What happens when you try to uncheck "Check_Approve"?

Hi!
   I checked it and in my opinion, this procedures like 'Check_Approval' (in your example) are procedures in API with the directive '--@PoReadOnly(Check_Approval)'
It means these procedures only return information and do not change any database data.
When you check any other procedure in this API, all Readonly procedures will be checked. 
Best regards,