delete from the output of a select query using postgres

I have a query that will run and allow me to find out if i have persons in the DB with more than one active account number. I was trying to setup this query to delete the additional accounts other than the one i specify i wanted to keep. The query is below, (the database layout is a lesson in relational db's and data is in multiple tables.

select c.id_value as Account_number, c.identifierdomain_key, d.id_value as Medical_Record_Number, a.admit_time, a.last_update_time, b.given_name as First_Name, b.family_name as Last_Name, l.nursing_unit as HIS_unit, l.bed as HIS_room_bed, l.encounterlocation_key, a.patient_key, a.encounter_key from encounter as a
inner join personname as b on a.patient_key = b.person_key
inner join encounteridentifier as c on a.encounter_key = c.encounter_key
inner join personidentifier as d on a.patient_key = d.person_key
inner join encounterlocation as l on a.assigned_location = l.encounterlocation_key
where a.patient_key in (select patient_key from encounter as a
group by a.patient_key
having count(a.patient_key) > 1 and d.id_value = '000000109')
order by last_name;

output of the query when i add this code below i get an error at the if line, i do have a secondary query that i can run that is the basis of the delete from lines where i pull the key values and that works. Just trying to make something iterate though and remove but cannot seem to link the two queries together as one

**if c.id_value != '12342'**
    **delete from ccg.ccg.encounter cascade**
    **where account_key = a.encounter_key;**

    **delete from ccg.ccg.account cascade**
    **where account_key = a.encounter_key;**

    **delete from ccg.ccg.encounterlocation**
    **where encounttion cascadeerlocation_key = l.encounterlocation_key;**

    **delete from ccg.ccg.identifierdomain cascade**
    **where identifierdomain_key = c.identifierdomain_key;**
   ** end if**

sort of stuck trying to figure out how to take actions on the results of my select statement to automate this process where i have the datapoints just cannot link them together