feat: table_field.fieldname field syntax for db_query

frappe/desk/reportview.py

@@ -171,7 +171,7 @@ def raise_invalid_field(fieldname):
 
 def is_standard(fieldname):
 	if "." in fieldname:
-		parenttype, fieldname = get_parenttype_and_fieldname(fieldname, None)
+		fieldname = fieldname.split(".")[1].strip("`")
 	return (
 		fieldname in default_fields or fieldname in optional_fields or fieldname in child_table_fields
 	)
@@ -235,7 +235,16 @@ def parse_json(data):
 
 def get_parenttype_and_fieldname(field, data):
 	if "." in field:
-		parenttype, fieldname = field.split(".")[0][4:-1], field.split(".")[1].strip("`")
+		parts = field.split(".")
+		parenttype = parts[0]
+		fieldname = parts[1]
+		if parenttype.startswith("`tab"):
+			# `tabChild DocType`.`fieldname`
+			parenttype = parenttype[4:-1]
+			fieldname = fieldname.strip("`")
+		else:
+			# tablefield.fieldname
+			parenttype = frappe.get_meta(data.doctype).get_field(parenttype).options
 	else:
 		parenttype = data.doctype
 		fieldname = field.strip("`")

frappe/model/db_query.py

@@ -287,6 +287,21 @@ class DatabaseQuery(object):
 		# remove empty strings / nulls in fields
 		self.fields = [f for f in self.fields if f]
 
+		# convert child_table.fieldname to `tabChild DocType`.`fieldname`
+		for field in self.fields:
+			if "." in field and "tab" not in field:
+				original_field = field
+				alias = None
+				if " as " in field:
+					field, alias = field.split(" as ")
+				tablefield, fieldname = field.split(".")
+				child_doctype = frappe.get_meta(self.doctype).get_field(tablefield).options
+				field = field.replace(tablefield, f"`tab{child_doctype}`")
+				field = field.replace(fieldname, f"`{fieldname}`")
+				if alias:
+					field = f"{field} as {alias}"
+				self.fields[self.fields.index(original_field)] = field
+
 		for filter_name in ["filters", "or_filters"]:
 			filters = getattr(self, filter_name)
 			if isinstance(filters, str):

frappe/tests/test_db_query.py

@@ -35,6 +35,22 @@ class TestReportview(unittest.TestCase):
 
 		clear_custom_fields("DocType")
 
+	def test_child_table_field_syntax(self):
+		note = frappe.get_doc(
+			doctype="Note",
+			title=f"Test {frappe.utils.random_string(8)}",
+			content="test",
+			seen_by=[{"user": "Administrator"}],
+		).insert()
+		result = frappe.db.get_all(
+			"Note",
+			filters={"name": note.name},
+			fields=["name", "seen_by.user as seen_by"],
+			limit=1,
+		)
+		self.assertEqual(result[0].seen_by, "Administrator")
+		note.delete()
+
 	def test_build_match_conditions(self):
 		clear_user_permissions_for_doctype("Blog Post", "test2@example.com")