Decryption Error in Query - postgresql

Question

I have a large query that encrypts/decrypts one table in PostgreSQL. I added a new conditional to this query and it now throws an error. The original query retrieves all records based on date and inner join relevance (all records from tblSessions that meet the conditions).
The updated query retrieves only records from tblSessions where parent_session_id is not null (any records from tblSessions that have a child record are omitted from results).
tblsessions (only showing fields that pertain to join conditions)
sessionid | decision_id | start_time | end_time | is_comlete | parent_session_id
---------------------------------------------------------------------------------
SERIAL | BYTEA | BYTEA | BYTEA | BYTEA | INTEGER DEFAULT 0
In the SQL window of Posgres, Running the second query gives me the following error:
ERROR: function decrypt(integer, "unknown", "unknown") does not exist
SQL state: 42883
Hint: No function matches the given name and argument types. You may need to add explicit type casts.
Original query (works):
SELECT z.conditionname, x.name AS domainname, d.decisionName,
c.firstname AS counselor_first_name, c.lastname AS counselor_last_name,
o.name AS organization_name,
encode(decrypt(s.start_time, '####salt####', '###encryption mode###'), 'escape') AS start_time,
encode(decrypt(s.end_time, '####salt####', '###encryption mode###'), 'escape') AS end_time,
encode(decrypt(s.is_complete, '####salt####', '###encryption mode###'), 'escape') AS is_complete,
s.parent_session_id
FROM tblDecisions d
INNER JOIN tblSessions s ON encode(decrypt(s.decision_id, '####salt####', '###encryption mode###'), 'escape') = d.decisionid
INNER JOIN tblCounselors c ON encode(decrypt(s.counselor_ck, '####salt####', '###encryption mode###'), 'escape') = c.campuskey
INNER JOIN tblCounselor_to_organization co ON co.counselor_id = c.counselorid
INNER JOIN tblOrganizations o ON o.organizationid = co.organization_id
INNER JOIN tblDomains x ON x.domainid = d.domain_id
INNER JOIN tblConditions z ON z.conditionid = x.condition_id
AND encode(decrypt(s.start_time, '####salt####', '###encryption mode###'), 'escape') >= '2012-01-01 00:00:00'
AND encode(decrypt(s.is_complete, '####salt####', '###encryption mode###'), 'escape') = 'true'
ORDER BY encode(decrypt(s.start_time, '####salt####', '###encryption mode###'), 'escape'), encode(decrypt(s.last_name, '####salt####', '###encryption mode###'), 'escape'), encode(decrypt(s.first_name, '####salt####', '###encryption mode###'), 'escape')
Revised query (doesn't work; commented additions below)
SELECT z.conditionname, x.name AS domainname, d.decisionName,
c.firstname AS counselor_first_name, c.lastname AS counselor_last_name,
o.name AS organization_name,
encode(decrypt(s.start_time, '####salt####', '###encryption mode###'), 'escape') AS start_time,
encode(decrypt(s.end_time, '####salt####', '###encryption mode###'), 'escape') AS end_time,
encode(decrypt(s.is_complete, '####salt####', '###encryption mode###'), 'escape') AS is_complete,
s.parent_session_id
//////// ADDITION START
, (SELECT MAX(encode(decrypt(start_time, '####salt####', '###encryption mode###'), 'escape')) AS start_time
FROM tblSessions s2
WHERE encode(decrypt(s2.parent_session_id, '####salt####', '###encryption mode###'), 'escape') = encode(decrypt(s.parent_session_id, '####salt####', '###encryption mode###'), 'escape') )
//////// ADDITION END
FROM tblDecisions d
INNER JOIN tblSessions s ON encode(decrypt(s.decision_id, '####salt####', '###encryption mode###'), 'escape') = d.decisionid
INNER JOIN tblCounselors c ON encode(decrypt(s.counselor_ck, '####salt####', '###encryption mode###'), 'escape') = c.campuskey
INNER JOIN tblCounselor_to_organization co ON co.counselor_id = c.counselorid
INNER JOIN tblOrganizations o ON o.organizationid = co.organization_id
INNER JOIN tblDomains x ON x.domainid = d.domain_id
INNER JOIN tblConditions z ON z.conditionid = x.condition_id
AND encode(decrypt(s.start_time, '####salt####', '###encryption mode###'), 'escape') >= '2012-01-01 00:00:00'
AND encode(decrypt(s.is_complete, '####salt####', '###encryption mode###'), 'escape') = 'true'
/////// ADDITION START
AND NOT EXISTS (
SELECT 1
FROM tblSessions s1
WHERE encode(decrypt(s1.parent_session_id, '####salt####', '###encryption mode###'), 'escape') = encode(decrypt(s.sessionid, '####salt####', '###encryption mode###'), 'escape') )
AND (
( encode(decrypt(s.parent_session_id, '####salt####', '###encryption mode###'), 'escape') IS NULL) OR
( encode(decrypt(s.start_time, '####salt####', '###encryption mode###'), 'escape') = (
SELECT MAX(encode(decrypt(start_time, '####salt####', '###encryption mode###'), 'escape')) AS start_time
FROM tblSessions s2
WHERE encode(decrypt(s2.parent_session_id, '####salt####', '###encryption mode###'), 'escape') = encode(decrypt(s.parent_session_id, '####salt####', '###encryption mode###'), 'escape')
)
)
)
///////// ADDITION END
ORDER BY encode(decrypt(s.start_time, '####salt####', '###encryption mode###'), 'escape'), encode(decrypt(s.last_name, '####salt####', '###encryption mode###'), 'escape'), encode(decrypt(s.first_name, '####salt####', '###encryption mode###'), 'escape')
I understand the error message, but that can't be the actual issue since all additions to the query have been properly decoded. Am I missing something obvious?

Answer 1

The question mentions that parent_session_id is type INTEGER but it is passed as the first argument to decrypt in the snippet below, unlike the rest of the code that seem to pass only bytea fields there.
decrypt(s.parent_session_id, '####salt####', '###encryption mode###')
This is likely to provokes the error mentioned, since there's no flavor of decrypt that takes an integer as the first argument (from the error message, could be confirmed with \df decrypt in psql)
Are you sure these session IDs are encrypted?