Replace frappe.db.sql to frappe.get_list to apply permissions (#14037)

* Replace frappe.db.sql to frappe.get_list to apply permission
- All get_children method had frappe.db.sql in them which
had no permission check, now its replaced with frappe.get_list
which will check permission based on the user.

* Fix codacy
- Remove trailing whitespace
diff --git a/erpnext/accounts/utils.py b/erpnext/accounts/utils.py
index ab194f4..b5d9cd8 100644
--- a/erpnext/accounts/utils.py
+++ b/erpnext/accounts/utils.py
@@ -660,29 +660,23 @@
 def get_children(doctype, parent, company, is_root=False):
 	from erpnext.accounts.report.financial_statements import sort_accounts
 
-	fieldname = frappe.db.escape(doctype.lower().replace(' ','_'))
-	doctype = frappe.db.escape(doctype)
-
-	# root
+	parent_fieldname = 'parent_' + doctype.lower().replace(' ', '_')
+	fields = [
+		'name as value',
+		'is_group as expandable'
+	]
+	filters = [['docstatus', '<', 2]]
 	if is_root:
-		fields = ", root_type, report_type, account_currency" if doctype=="Account" else ""
-		acc = frappe.db.sql(""" select
-			name as value, is_group as expandable {fields}
-			from `tab{doctype}`
-			where ifnull(`parent_{fieldname}`,'') = ''
-			and `company` = %s	and docstatus<2
-			order by name""".format(fields=fields, fieldname = fieldname, doctype=doctype),
-				company, as_dict=1)
+		fields += ['root_type', 'report_type', 'account_currency'] if doctype == 'Account' else []
+		filters.append([parent_fieldname, '=', ''])
+		filters.append(['company', '=', company])
+
 	else:
-		# other
-		fields = ", account_currency" if doctype=="Account" else ""
-		acc = frappe.db.sql("""select
-			name as value, is_group as expandable, parent_{fieldname} as parent {fields}
-			from `tab{doctype}`
-			where ifnull(`parent_{fieldname}`,'') = %s
-			and docstatus<2
-			order by name""".format(fields=fields, fieldname=fieldname, doctype=doctype),
-				parent, as_dict=1)
+		fields += ['account_currency'] if doctype == 'Account' else []
+		fields += [parent_fieldname + ' as parent']
+
+
+	acc = frappe.get_list(doctype, fields=fields, filters=filters)
 
 	if doctype == 'Account':
 		sort_accounts(acc, is_root, key="value")
diff --git a/erpnext/agriculture/doctype/land_unit/land_unit.py b/erpnext/agriculture/doctype/land_unit/land_unit.py
index f577eca..35bda1c 100644
--- a/erpnext/agriculture/doctype/land_unit/land_unit.py
+++ b/erpnext/agriculture/doctype/land_unit/land_unit.py
@@ -169,11 +169,10 @@
 	if is_root:
 		parent = ''
 
-	land_units = frappe.db.sql("""select name as value,
-		is_group as expandable
-		from `tabLand Unit`
-		where ifnull(`parent_land_unit`,'') = %s
-		order by name""", (parent), as_dict=1)
+	land_units = frappe.get_list(doctype,
+		fields = ['name as value', 'is_group as expandable'],
+		filters= [['parent_land_unit', '=', parent]],
+		order_by='name')
 
 	# return nodes
 	return land_units
diff --git a/erpnext/hr/doctype/employee/employee.py b/erpnext/hr/doctype/employee/employee.py
index 824ddf5..93f6532 100755
--- a/erpnext/hr/doctype/employee/employee.py
+++ b/erpnext/hr/doctype/employee/employee.py
@@ -318,26 +318,26 @@
 
 @frappe.whitelist()
 def get_children(doctype, parent=None, company=None, is_root=False, is_tree=False):
-	condition = ''
+	filters = [['company', '=', company]]
+	fields = ['name as value', 'employee_name as title']
 
 	if is_root:
-		parent = ""
+		parent = ''
 	if parent and company and parent!=company:
-		condition = ' and reports_to = "{0}"'.format(frappe.db.escape(parent))
+		filters.append(['reports_to', '=', parent])
 	else:
-		condition = ' and ifnull(reports_to, "")=""'
+		filters.append(['reports_to', '=', ''])
 
-	employee = frappe.db.sql("""
-		select
-			name as value, employee_name as title,
-			exists(select name from `tabEmployee` where reports_to=emp.name) as expandable
-		from
-			`tabEmployee` emp
-		where company='{company}' {condition} order by name"""
-		.format(company=company, condition=condition),  as_dict=1)
+	employees = frappe.get_list(doctype, fields=fields,
+		filters=filters, order_by='name')
 
-	# return employee
-	return employee
+	for employee in employees:
+		is_expandable = frappe.get_all(doctype, filters=[
+			['reports_to', '=', employee.get('value')]
+		])
+		employee.expandable = 1 if is_expandable else 0
+
+	return employees
 
 
 def on_doctype_update():
diff --git a/erpnext/manufacturing/doctype/bom/bom.py b/erpnext/manufacturing/doctype/bom/bom.py
index 1fbc806..559bbdf 100644
--- a/erpnext/manufacturing/doctype/bom/bom.py
+++ b/erpnext/manufacturing/doctype/bom/bom.py
@@ -624,18 +624,28 @@
 		return
 
 	if frappe.form_dict.parent:
-		return frappe.db.sql("""select
-			bom_item.item_code,
-			bom_item.bom_no as value,
-			bom_item.stock_qty,
-			if(ifnull(bom_item.bom_no, "")!="", 1, 0) as expandable,
-			item.image,
-			item.description
-			from `tabBOM Item` bom_item, tabItem item
-			where bom_item.parent=%s
-			and bom_item.item_code = item.name
-			order by bom_item.idx
-			""", frappe.form_dict.parent, as_dict=True)
+		bom_items = frappe.get_list('BOM Item',
+			fields=['item_code', 'bom_no as value', 'stock_qty'],
+			filters=[['parent', '=', frappe.form_dict.parent]],
+			order_by='idx')
+
+		item_names = tuple(d.get('item_code') for d in bom_items)
+
+		items = frappe.get_list('Item',
+			fields=['image', 'description', 'name'],
+			filters=[['name', 'in', item_names]]) # to get only required item dicts
+
+		for bom_item in bom_items:
+			# extend bom_item dict with respective item dict
+			bom_item.update(
+				# returns an item dict from items list which matches with item_code
+				(item for item in items if item.get('name')
+					== bom_item.get('item_code')).next()
+			)
+			bom_item.expandable = 0 if bom_item.value in ('', None)  else 1
+
+		return bom_items
+
 
 def get_boms_in_bottom_up_order(bom_no=None):
 	def _get_parent(bom_no):
diff --git a/erpnext/projects/doctype/task/task.py b/erpnext/projects/doctype/task/task.py
index fcaa344..c86e699 100644
--- a/erpnext/projects/doctype/task/task.py
+++ b/erpnext/projects/doctype/task/task.py
@@ -186,27 +186,25 @@
 
 @frappe.whitelist()
 def get_children(doctype, parent, task=None, project=None, is_root=False):
-	conditions = ''
+
+	filters = [['docstatus', '<', '2']]
 
 	if task:
-		# via filters
-		conditions += ' and parent_task = "{0}"'.format(frappe.db.escape(task))
+		filters.append(['parent_task', '=', task])
 	elif parent and not is_root:
 		# via expand child
-		conditions += ' and parent_task = "{0}"'.format(frappe.db.escape(parent))
+		filters.append(['parent_task', '=', parent])
 	else:
-		conditions += ' and ifnull(parent_task, "")=""'
+		filters.append(['parent_task', '=', ''])
 
 	if project:
-		conditions += ' and project = "{0}"'.format(frappe.db.escape(project))
+		filters.append(['project', '=', project])
 
-	tasks = frappe.db.sql("""select name as value,
-		subject as title,
-		is_group as expandable
-		from `tabTask`
-		where docstatus < 2
-		{conditions}
-		order by name""".format(conditions=conditions), as_dict=1)
+	tasks = frappe.get_list(doctype, fields=[
+		'name as value',
+		'subject as title',
+		'is_group as expandable'
+	], filters=filters, order_by='name')
 
 	# return tasks
 	return tasks
diff --git a/erpnext/stock/doctype/warehouse/warehouse.py b/erpnext/stock/doctype/warehouse/warehouse.py
index 9c47f98..b90ee32 100644
--- a/erpnext/stock/doctype/warehouse/warehouse.py
+++ b/erpnext/stock/doctype/warehouse/warehouse.py
@@ -144,17 +144,19 @@
 	if is_root:
 		parent = ""
 
-	warehouses = frappe.db.sql("""select name as value,
-		is_group as expandable
-		from `tabWarehouse`
-		where docstatus < 2
-		and ifnull(`parent_warehouse`,'') = %s
-		and (`company` = %s or company is null or company = '')
-		order by name""", (parent, company), as_dict=1)
+	fields = ['name as value', 'is_group as expandable']
+	filters = [
+		['docstatus', '<', '2'],
+		['parent_warehouse', '=', parent],
+		['company', 'in', (company, None,'')]
+	]
+
+	warehouses = frappe.get_list(doctype, fields=fields, filters=filters, order_by='name')
 
 	# return warehouses
 	for wh in warehouses:
 		wh["balance"] = get_stock_value_on(warehouse=wh.value)
+
 	return warehouses
 
 @frappe.whitelist()