diff --git a/erpnext/buying/doctype/supplier/supplier.py b/erpnext/buying/doctype/supplier/supplier.py
index 120b2f8..01b5c8f 100644
--- a/erpnext/buying/doctype/supplier/supplier.py
+++ b/erpnext/buying/doctype/supplier/supplier.py
@@ -125,18 +125,9 @@
 
 	def on_trash(self):
 		if self.supplier_primary_contact:
-			frappe.db.sql(
-				"""
-				UPDATE `tabSupplier`
-				SET
-					supplier_primary_contact=null,
-					supplier_primary_address=null,
-					mobile_no=null,
-					email_id=null,
-					primary_address=null
-				WHERE name=%(name)s""",
-				{"name": self.name},
-			)
+			self.db_set("supplier_primary_contact", None)
+		if self.supplier_primary_address:
+			self.db_set("supplier_primary_address", None)
 
 		delete_contact_and_address("Supplier", self.name)
 
diff --git a/erpnext/selling/doctype/customer/customer.py b/erpnext/selling/doctype/customer/customer.py
index d9dab33..baa316f 100644
--- a/erpnext/selling/doctype/customer/customer.py
+++ b/erpnext/selling/doctype/customer/customer.py
@@ -272,18 +272,9 @@
 
 	def on_trash(self):
 		if self.customer_primary_contact:
-			frappe.db.sql(
-				"""
-				UPDATE `tabCustomer`
-				SET
-					customer_primary_contact=null,
-					customer_primary_address=null,
-					mobile_no=null,
-					email_id=null,
-					primary_address=null
-				WHERE name=%(name)s""",
-				{"name": self.name},
-			)
+			self.db_set("customer_primary_contact", None)
+		if self.customer_primary_address:
+			self.db_set("customer_primary_address", None)
 
 		delete_contact_and_address("Customer", self.name)
 		if self.lead_name: