diff --git a/frappe/utils/error.py b/frappe/utils/error.py
index c38b320d98..ba0fbf1605 100644
--- a/frappe/utils/error.py
+++ b/frappe/utils/error.py
@@ -176,9 +176,13 @@ def collect_error_snapshots():
 
 def clear_old_snapshots():
 	"""Clear snapshots that are older than a month"""
+	from frappe.query_builder import DocType, Interval
+	from frappe.query_builder.functions import Now
 
-	frappe.db.sql("""delete from `tabError Snapshot`
-		where creation < (NOW() - INTERVAL '1' MONTH)""")
+	ErrorSnapshot = DocType("Error Snapshot")
+	frappe.db.delete(ErrorSnapshot, filters=(
+		ErrorSnapshot.creation < (Now() - Interval(months=1))
+	))
 
 	path = get_error_snapshot_path()
 	today = datetime.datetime.now()
diff --git a/frappe/utils/install.py b/frappe/utils/install.py
index ac26a98eb6..d197304c98 100644
--- a/frappe/utils/install.py
+++ b/frappe/utils/install.py
@@ -34,7 +34,7 @@ def after_install():
 	print_settings.save()
 
 	# all roles to admin
-	frappe.get_doc("User", "Administrator").add_roles(*frappe.db.sql_list("""select name from tabRole"""))
+	frappe.get_doc("User", "Administrator").add_roles(*frappe.get_all("Role", pluck="name"))
 
 	# update admin password
 	update_password("Administrator", get_admin_password())
diff --git a/frappe/utils/user.py b/frappe/utils/user.py
index ca7a555c72..c84b29b1c9 100644
--- a/frappe/utils/user.py
+++ b/frappe/utils/user.py
@@ -64,14 +64,14 @@ class UserPermissions:
 
 	def build_doctype_map(self):
 		"""build map of special doctype properties"""
+		self.doctype_map = {}
 
 		active_domains = frappe.get_active_domains()
+		all_doctypes = frappe.get_all("DocType", fields=["name", "in_create", "module", "istable", "issingle", "read_only", "restrict_to_domain"])
 
-		self.doctype_map = {}
-		for r in frappe.db.sql("""select name, in_create, issingle, istable,
-			read_only, restrict_to_domain, module from tabDocType""", as_dict=1):
-			if (not r.restrict_to_domain) or (r.restrict_to_domain in active_domains):
-				self.doctype_map[r['name']] = r
+		for dt in all_doctypes:
+			if not dt.restrict_to_domain or (dt.restrict_to_domain in active_domains):
+				self.doctype_map[dt["name"]] = dt
 
 	def build_perm_map(self):
 		"""build map of permissions at level 0"""