如果工人 ID 排序不重要，请使用内置聚合函数。
SQL> select id, min(start_date), max(case when last_worker is not null then end_date end) end_date,
2 wm_concat(worker_id) worker_ids, max(last_worker) last_worker
3 from (select id, start_date, end_date, end_code, worker_id, case when end_code ='J' or end_date is null then worker_id end last_worker,
4 nvl(max(r) over (partition by id order by end_date nulls last), 1) r
5 from (select t.*,
6 case
7 when lag(end_code, 1) over (partition by id order by end_date nulls last) = 'J' then
8 row_number() over(partition by id order by end_date nulls last)
9 end r
10 from test t)
11 )
12 group by id, r;
I MIN(START END_DATE WORKER_IDS LAST_WORKER
- --------- --------- -------------------- -----------
A 02-AUG-03 17-NOV-08 1,2 2
A 03-MAR-09 3,6,5,4 6
是吗，您必须创建自己的聚合函数。例如，这是我在 10g 上使用的：
SQL> select id, min(start_date), max(case when last_worker is not null then end_date end) end_date,
2 stragg_num(stragg_num_typ(worker_id, ',', worker_id)) worker_ids, max(last_worker) last_worker
3 from (select id, start_date, end_date, end_code, worker_id, case when end_code ='J' or end_date is null then worker_id end last_worker,
4 nvl(max(r) over (partition by id order by end_date nulls last), 1) r
5 from (select t.*,
6 case
7 when lag(end_code, 1) over (partition by id order by end_date nulls last) = 'J' then
8 row_number() over(partition by id order by end_date nulls last)
9 end r
10 from test t)
11 )
12 group by id, r;
I MIN(START END_DATE WORKER_IDS LAST_WORKER
- --------- --------- -------------------- -----------
A 02-AUG-03 17-NOV-08 1,2 2
A 03-MAR-09 3,4,5,6 6
SQL>
其中的定义是：
drop function stragg;
drop function stragg_num;
drop type string_agg_type;
drop type stragg_vc_tab;
drop type stragg_vc_typ;
drop type stragg_num_tab;
drop type stragg_num_typ;
create or replace type stragg_vc_typ as object
(
value varchar2(4000),
delim varchar2(10),
rown varchar2(4000)
);
/
create or replace type stragg_vc_tab
as table of stragg_vc_typ;
/
show errors type stragg_vc_tab
create or replace type stragg_num_typ as object
(
value varchar2(4000),
delim varchar2(10),
rown integer
);
/
show errors type stragg_num_typ
create or replace type stragg_num_tab
as table of stragg_num_typ;
/
show errors type stragg_num_tab
create or replace type string_agg_type as object
(
total clob,
delim varchar2(10),
data stragg_num_tab,
data2 stragg_vc_tab,
static function
ODCIAggregateInitialize(sctx IN OUT string_agg_type )
return number,
member function
ODCIAggregateIterate(self IN OUT string_agg_type ,
value IN stragg_num_typ )
return number,
member function
ODCIAggregateIterate(self IN OUT string_agg_type ,
value IN stragg_vc_typ )
return number,
member function
ODCIAggregateTerminate(self IN string_agg_type,
returnValue OUT varchar2,
flags IN number)
return number,
member function
ODCIAggregateMerge(self IN OUT string_agg_type,
ctx2 IN string_agg_type)
return number
);
/
show errors type string_agg_type
create or replace type body string_agg_type
is
static function ODCIAggregateInitialize(sctx IN OUT string_agg_type)
return number
is
begin
sctx := string_agg_type( null, null, null, null );
return ODCIConst.Success;
end;
member function ODCIAggregateIterate(self IN OUT string_agg_type,
value IN stragg_num_typ )
return number
is
begin
if (delim is null)
then
delim := value.delim;
end if;
if (data is null)
then
data := stragg_num_tab();
end if;
data.extend;
data(data.last) := value;
return ODCIConst.Success;
end;
member function ODCIAggregateIterate(self IN OUT string_agg_type,
value IN stragg_vc_typ )
return number
is
begin
if (delim is null)
then
delim := value.delim;
end if;
if (data2 is null)
then
data2 := stragg_vc_tab();
end if;
data2.extend;
data2(data2.last) := value;
return ODCIConst.Success;
end;
member function ODCIAggregateTerminate(self IN string_agg_type,
returnValue OUT varchar2,
flags IN number)
return number
is
v_delim varchar2(10);
begin
if data is not null
then
for r_item in (select d.value
from table(data) d
order by d.rown)
loop
returnValue := returnValue || v_delim || r_item.value;
v_delim := self.delim;
end loop;
else
for r_item in (select d.value
from table(data2) d
order by d.rown)
loop
returnValue := returnValue || v_delim || r_item.value;
v_delim := self.delim;
end loop;
end if;
return ODCIConst.Success;
end;
member function ODCIAggregateMerge(self IN OUT string_agg_type,
ctx2 IN string_agg_type)
return number
is
begin
self.total := self.total || ctx2.total;
return ODCIConst.Success;
end;
end;
/
show errors type body string_agg_type
CREATE or replace FUNCTION stragg_num(input stragg_num_typ )
RETURN varchar2
PARALLEL_ENABLE AGGREGATE USING string_agg_type;
/
CREATE or replace FUNCTION stragg(input stragg_vc_typ )
RETURN varchar2
PARALLEL_ENABLE AGGREGATE USING string_agg_type;
/