My app got an error with message like this : “An error occurred while initializing the Runtime: Detected unique constraint violation [entity: MyFirstModule.Course, attribute: Title] Since Mendix 9, only Database Uniqueness Validation is supported. If your project still uses Runtime Uniqueness Validation, please contact support.” Please guide me where to check my database ?
Hi Ngoc Vo,
First remove the Validation rule in the entity Course for the attribute Title. Then run the project and in console there would be Advanced drop down. Click on advanced and select the Start built in database viewer, there you can see all the tables. Delete the required records in the Course table. Delete the empty title records as well. After running the app again. You can keep your Uniqueness validation again.