1. By listing the distinct values in a table.
2. By querying for NULL values in a table. 
3. By querying the table with a GROUP BY and a HAVING count(*) > 2.
4. Acquaint yourself with the data and create a data dictionary.
5. A document that helps you to understand what is in your database.
6. First, you will need to install a Python plugin into your MySQL Workbench installation, then create an ERD. Next, you can use the Python plugin to create the data dictionary to paste into a text or markdown editor of your choice.
7. They help search for string patterns in your data.
8. Matches the beginning of a string.
9. Matches any of the patterns specified. 
10. Yes. WHERE column REGEXP '^[abc].{3}on$'