I want to generate the partition name by querying dba_tab_partitions and drop the oldest partition


declare
part_name varchar2(10);
drop_part varchar2(1000);
begin
select partition_name into part_name from dba_tab_partitions where (table_name='ORDERITEM_TEMP' and rownum=1);
select 'alter table orderitem_temp truncate partition "'
||'part_name'
||'update global indexes'"' into drop_part from dual;
execute immediate drop_part;
end;
/

ERROR MESG---------------------------------------------------------
Error starting at line 2 in command:
declare
myname varchar2(10);
myname2 varchar2(1000);
begin
select partition_name into myname from dba_tab_partitions where (table_name='ORDERITEM_TEMP' and rownum=1);
select 'alter table orderitem_temp drop partition "'
||'myname'
||'update global indexes'"' into myname2 from dual;
execute immediate myname2;
end;
Error report:
ORA-06550: line 8, column 27:
PLS-00112: end-of-line in quoted identifier
ORA-06550: line 8, column 28:
PL/SQL: ORA-00972: identifier is too long
ORA-06550: line 6, column 2:
PL/SQL: SQL Statement ignored
06550. 00000 - "line %s, column %s:\n%s"
*Cause: Usually a PL/SQL compilation error.
*Action:


Kindly suggest where I went wrong.

declare 

part_name varchar2(10);
drop_part varchar2(1000);

begin

  select partition_name into part_name from dba_tab_partitions 
 where (table_name='ORDERITEM_TEMP' and rownum=1); 
  drop_part := 'alter table orderitem_temp truncate partition '|| part_name || ' update global indexes';

  execute immediate drop_part;
end;
/