Method presented from 4:20
Ok. This method (adding the WHERE clause) will work fine in this particular case you described -> but I understand that it is not a general rule?
Let's assume that in the area marked as 1 from the screen above - we have departments that have NULL values in the dep_name column.
in this case statement "WHERE dept_name IS NULL" won't enable us to get only the area 2 right?
Thanks for reaching out.
Can you please be more specific? I.e., can you please support your question with a particular query you are referring to, as well as specify which table is on the left, and which, on the right (conceptually, of course). Also, please confirm that the dept_name field is the one that is common between the two tables, as shown the graph. Thank you.
Looking forward to your reply..