Issue in upgrading OJS 2.4 to OJS 3.x

Software Support
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I am upgrading from OJS 2.4 to 3.x and encountering a number of problems including;

review_assignments_tmp already exists
notes_tmp already exists
submission_galley_settings already exists

I deleted these and then encountered the following error;
DB Error: Unknown column 'assoc_type' in 'where clause' Query: UPDATE email_templates SET assoc_type = 530 WHERE assoc_type = '526'

I have then cleared data for these and re run the upgrade process but now encountering the following error;

# DB Error: Unknown column 'a.setting_type' in 'where clause' Query: SELECT a.*, b.context_id FROM submission_settings a, submissions b WHERE a.setting_name = 'fileName' AND a.locale = ? AND a.setting_value LIKE ? AND a.setting_type = 'string' AND b.submission_id = a.submission_id

Is there any way to clean/ check the database as I have the same database in the backup. How can we check if our data is good to be upgraded to OJS 3.x