Resolved: Quotation marks for INT column
For the second query, the answer file lists the WHERE clause as
WHERE emp_no NOT BETWEEN '10004' AND '10012'. However, since emp_no is of type INT(11), wouldn't it make more sense to leave out the quotation marks for the numbers?
Thanks for reaching out!
Yes, if a column is of type INT you can simply remove the quotes. However, if the column is of type DATE, omitting the quotes will result in a different result set. The date 2010-02-03 will be calculated
as 2010-2-3=2005. So, we want a range from 2010-02-03 but instead it is being calculated as a range starting from 2005. So, we should use quotes with dates like this – '2010-02-03'.
Hope this helps.
The explanation regarding where to use quotation marks and where to not has been scattered during the course, while I see by this comment of yours that it is a really important tip to remember, I hope it is explained further ahead and if not, you add a video exlpaining it completely once forever.