Sqlite. Loop through rows and match, break when value is equal - sql

Question

Could anyone suggest please is it possible to break recursion function if circular dependency happend ? As soon as I encounter that s.Part_Ptr = s.Substituent_Ptr I want to break Loop and return result.
with SubstitutionRecursion as (select Part_Ptr, Substituent_Ptr from model_2271_substitute where Part_Ptr = 24588687861243
union all
select s.Part_Ptr, s.Substituent_Ptr from SubstitutionRecursion sr
left join model_2271_substitute s on s.Part_Ptr = sr.Substituent_Ptr
where s.Substituent_Ptr is not null)
select p.partCode, p.partDescription, p.notes from SubstitutionRecursion sr
left join model_2271_all_parts p on p.PartPtr = sr.Substituent_Ptr;

Answer 1

You would typically keep track of the visited nodes in another column of the CTE, and stop the recursion when an already visited node is met.
Your question does not show sample data, which makes it a bit more complicated to answer, but the logic would look like:
with substitutionrecursion as (
select part_ptr, substituent_ptr, '/' || substituent_ptr || '/' path
from model_2271_substitute
where part_ptr = 24588687861243
union all
select s.part_ptr, s.substituent_ptr, sr.path || s.substituent_ptr || '/'
from substitutionrecursion sr
inner join model_2271_substitute s on s.part_ptr = sr.substituent_ptr
where s.substituent_ptr not like '%/' || sr.path || '/%'
)
select ...
path is a string column that concatenates the visited substituent_ptrs.