Problems with updating the database using code first migrations

Error message: the 'title' Column cannot be inserted with a null value. Table 'mvccorperation. Models. corperationdbcontext. DBO. Articles '; the column cannot have a null value. Update failed.

The statement has been terminated.

Environment: A database table already exists. The database table also has data. I just added dataannotations to the model, and then used the add-migration and update-database commands to prompt the above error.

Cause of error: the original database contains data records that do not meet the new constraints. The title field of a record is null, and the new condition is that the title field cannot be null.

Solution: Before executing Update-database, make sure that the data records in the database meet the new constraints. If any, an error is returned. I deleted the data and re-executed the update-database operation.