merge into aff_trial_source_label a
using (select name from affiliate_parent) p
on (a.source=p.name)
when matched then update set a.source=p.name
when not matched then insert(a.source_label_id,a.source,a.source_label) values(aff_trial_source_seq.nextval,p.name,p.name)



7 on (a.source=p.name)
*
ERROR at line 3:
ORA-00904: "A"."SOURCE": invalid identifier

the column name does exist in the table:

SQL> desc aff_trial_source_label
Name Null? Type
----------------------------------------- -------- ----------------------------
SOURCE_LABEL_ID NUMBER(13)
SOURCE VARCHAR2(512)
SOURCE_LABEL VARCHAR2(512)



any insight would be helpful.
thanks.