[Koha] Need SQL query help, please

[Carol Kresge]

I have a query to find borrowers with late books that do not have email
addresses or mobiles. Now I am trying to modify it so it will show their
school from attributes if they have one but won't knock them off the list
if they don't. My modification below  shows only those with no email and no
mobile and a school but knocks people off the list who have no school
attribute. How can I modify it so it includes no mobile no email and lists
school for those who have one but still includes those who don't?

SELECT
borrowers.surname,borrowers.firstname,borrowers.mobile,borrowers.email,borrowers.city,
biblio.title,biblioitems.itemtype,issues.date_due,borrower_attributes.attribute
FROM borrowers
LEFT JOIN borrower_attributes on (borrower_attributes.borrowernumber =
borrowers.borrowernumber)
LEFT JOIN issues on (issues.borrowernumber = borrowers.borrowernumber)
LEFT JOIN items on (items.itemnumber = issues.itemnumber)
LEFT JOIN biblioitems on
(items.biblioitemnumber=biblioitems.biblioitemnumber)
LEFT JOIN biblio on (biblioitems.biblionumber=biblio.biblionumber)
WHERE issues.date_due < DATE_SUB(now(), INTERVAL 8 DAY) AND
issues.returndate IS NULL AND borrowers.mobile = ' ' AND borrowers.email =
' ' AND borrower_attributes.code = 'School' ORDER BY borrowers.surname asc;

Thanks for your help!
Carol
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