[minor] passed index for string format
diff --git a/erpnext/schools/doctype/student_group/student_group.py b/erpnext/schools/doctype/student_group/student_group.py
index 9822d90..26bd311 100644
--- a/erpnext/schools/doctype/student_group/student_group.py
+++ b/erpnext/schools/doctype/student_group/student_group.py
@@ -112,7 +112,7 @@
 			tuple(students + ["%%%s%%" % txt, start, page_len]))
 	else:
 		return frappe.db.sql("""select name, title from tabStudent
-			where `{}` LIKE %s
+			where `{0}` LIKE %s
 			order by idx desc, name
 			limit %s, %s""".format(searchfield),
 			tuple(["%%%s%%" % txt, start, page_len]))