Passed parameter value to be checked with the retrieved column value

Question

select app.compositename,
(select distinct stringvalue from WFMESSAGEATTRIBUTE where taskid = APP.taskid and name = 'approverPayload') as APPROVERPAYLOAD,
                                 from DEVT_SOAINFRA.WFTASK APP
                               where APP.TEXTATTRIBUTE6 not like 'Product Data%'
                               and (:P_REQUESTTYPE like '%JobCha%')
                               and (:P_APPROVERID is null or
                                               upper(nvl(APPROVERPAYLOAD,'-1')) like upper(:P_APPROVERID || ',%') or
                                               upper(nvl(APPROVERPAYLOAD,'-1')) like upper('%,'||:P_APPROVERID ||',%') or
                                               upper(nvl(APPROVERPAYLOAD,'-1')) like upper(:P_APPROVERID)
                                                                         above is my query and iam retriving approverpayload based on below select statement
                                                                         (select distinct stringvalue from WFMESSAGEATTRIBUTE where taskid = APP.taskid and name = 'approverPayload')
                                                                                                            and in the where conditions can i check the passed parameter :P_APPROVERID exists in the APPROVERPAYLOAD as i have tried below
                                                                         and (:P_APPROVERID is null or
                                               upper(nvl(APPROVERPAYLOAD,'-1')) like upper(:P_APPROVERID || ',%') or
                                               upper(nvl(APPROVERPAYLOAD,'-1')) like upper('%,'||:P_APPROVERID ||',%') or
                                               upper(nvl(APPROVERPAYLOAD,'-1')) like upper(:P_APPROVERID)
                                                                                                            is my attempt correct if not can any one suggest me how to write it so.

Answer 1

You cannot use the column alias in the same level in the where clause as you are doing it. It needs to be done one level higher. So it will look something like this.
select * from
   select <column_name> <new_column_alias>
   from <table_name>
where <new_column_alias> <operator> <condition>Regards
Raj