diff --git a/frappe/database/query.py b/frappe/database/query.py
index c8e1ddabc6..6295c4ec3e 100644
--- a/frappe/database/query.py
+++ b/frappe/database/query.py
@@ -462,7 +462,8 @@ class Query:
 
 					fields = updated_fields
 
-		if not is_list:
+		# Need to check instance again since fields modified.
+		if not isinstance(fields, (list, tuple, set)):
 			fields = [fields] if fields else []
 
 		fields.extend(function_objects)
diff --git a/frappe/integrations/doctype/webhook/__init__.py b/frappe/integrations/doctype/webhook/__init__.py
index 077b39101e..915d2819ee 100644
--- a/frappe/integrations/doctype/webhook/__init__.py
+++ b/frappe/integrations/doctype/webhook/__init__.py
@@ -25,7 +25,7 @@ def run_webhooks(doc, method):
 			# query webhooks
 			webhooks_list = frappe.get_all(
 				"Webhook",
-				fields=["name", "condition", "webhook_docevent", "webhook_doctype"],
+				fields=["name", "`condition`", "webhook_docevent", "webhook_doctype"],
 				filters={"enabled": True},
 			)
 
diff --git a/frappe/model/db_query.py b/frappe/model/db_query.py
index b9c757bfa6..fe52818235 100644
--- a/frappe/model/db_query.py
+++ b/frappe/model/db_query.py
@@ -89,9 +89,6 @@ class DatabaseQuery(object):
 		ignore_ddl=False,
 		parent_doctype=None,
 	) -> List:
-		from frappe.database.query import Query
-
-		self.query = Query()
 
 		if (
 			not ignore_permissions
@@ -115,8 +112,6 @@ class DatabaseQuery(object):
 			# if `filters` is a list of strings, its probably fields
 			filters, fields = fields, filters
 
-		self.temp_filters, self.temp_fields = filters, fields
-
 		if fields:
 			self.fields = fields
 		else:
@@ -202,6 +197,7 @@ class DatabaseQuery(object):
 			%(limit)s"""
 			% args
 		)
+
 		return frappe.db.sql(
 			query,
 			as_dict=not self.as_list,
diff --git a/frappe/query_builder/functions.py b/frappe/query_builder/functions.py
index 7b260098d1..b55eff4298 100644
--- a/frappe/query_builder/functions.py
+++ b/frappe/query_builder/functions.py
@@ -95,6 +95,8 @@ class SqlFunctions(Enum):
 	Count = "count"
 	Sum = "sum"
 	Avg = "avg"
+	Max = "max"
+	Min = "min"
 
 
 def _max(dt, fieldname, filters=None, **kwargs):
diff --git a/frappe/share.py b/frappe/share.py
index 2933017048..3edcb1be38 100644
--- a/frappe/share.py
+++ b/frappe/share.py
@@ -104,12 +104,12 @@ def get_users(doctype, name):
 	return frappe.db.get_all(
 		"DocShare",
 		fields=[
-			"name",
-			"user",
-			"read",
-			"write",
-			"submit",
-			"share",
+			"`name`",
+			"`user`",
+			"`read`",
+			"`write`",
+			"`submit`",
+			"`share`",
 			"everyone",
 			"owner",
 			"creation",
diff --git a/frappe/tests/test_query.py b/frappe/tests/test_query.py
index 949c3e9433..d7190fe7ae 100644
--- a/frappe/tests/test_query.py
+++ b/frappe/tests/test_query.py
@@ -1,11 +1,12 @@
 import unittest
 
 import frappe
+from frappe.query_builder import Field
 from frappe.tests.test_query_builder import db_type_is, run_only_if
 
 
-@run_only_if(db_type_is.MARIADB)
 class TestQuery(unittest.TestCase):
+	@run_only_if(db_type_is.MARIADB)
 	def test_multiple_tables_in_filters(self):
 		self.assertEqual(
 			frappe.db.query.get_sql(
@@ -18,3 +19,55 @@ class TestQuery(unittest.TestCase):
 			).get_sql(),
 			"SELECT * FROM `tabDocType` LEFT JOIN `tabBOM Update Log` ON `tabBOM Update Log`.`parent`=`tabDocType`.`name` WHERE `tabBOM Update Log`.`name` LIKE 'f%' AND `tabDocType`.`parent`='something'",
 		)
+
+	def test_string_fields(self):
+		self.assertEqual(
+			frappe.db.query.get_sql("User", fields="name, email", filters={"name": "Administrator"}),
+			frappe.qb.from_("User")
+			.select(Field("name"), Field("email"))
+			.where(Field("name") == "Administrator"),
+		)
+
+		self.assertEqual(
+			frappe.db.query.get_sql("User", fields=["name, email"], filters={"name": "Administrator"}),
+			frappe.qb.from_("User")
+			.select(Field("name"), Field("email"))
+			.where(Field("name") == "Administrator"),
+		)
+
+	def test_functions_fields(self):
+		from frappe.query_builder.functions import Count
+
+		self.assertEqual(
+			frappe.db.query.get_sql("User", fields="Count(name)", filters={}),
+			frappe.qb.from_("User").select(Count(Field("name"))),
+		)
+
+		self.assertEqual(
+			frappe.db.query.get_sql("User", fields="Count(name), Max(name)", filters={}),
+			frappe.qb.from_("User").select(Count(Field("name")), Max(Field("name"))),
+		)
+
+		self.assertEqual(
+			frappe.db.query.get_sql("User", fields=["Count(name)", "Max(name)"], filters={}),
+			frappe.qb.from_("User").select(Count(Field("name")), Max(Field("name"))),
+		)
+
+		self.assertEqual(
+			frappe.db.query.get_sql("User", fields=[Count("*")], filters={}),
+			frappe.qb.from_("User").select(Count(Field("name")), Max(Field("name"))),
+		)
+
+	def test_qb_fields(self):
+		user_doctype = frappe.qb.DocType("User")
+		self.assertEqual(
+			frappe.db.query.get_sql(
+				user_doctype, fields=[user_doctype.name, user_doctype.email], filters={}
+			),
+			frappe.qb.from_(user_doctype).select(user_doctype.name, user_doctype.email),
+		)
+
+		self.assertEqual(
+			frappe.db.query.get_sql(user_doctype, fields=user_doctype.email, filters={}),
+			frappe.qb.from_(user_doctype).select(user_doctype.email),
+		)
diff --git a/frappe/workflow/doctype/workflow_action/workflow_action.py b/frappe/workflow/doctype/workflow_action/workflow_action.py
index 545ad6ec77..038a3021d2 100644
--- a/frappe/workflow/doctype/workflow_action/workflow_action.py
+++ b/frappe/workflow/doctype/workflow_action/workflow_action.py
@@ -290,7 +290,7 @@ def update_completed_workflow_actions_using_user(doc, user=None):
 def get_next_possible_transitions(workflow_name, state, doc=None):
 	transitions = frappe.get_all(
 		"Workflow Transition",
-		fields=["allowed", "action", "state", "allow_self_approval", "next_state", "condition"],
+		fields=["allowed", "action", "state", "allow_self_approval", "next_state", "`condition`"],
 		filters=[["parent", "=", workflow_name], ["state", "=", state]],
 	)