Oracle 11g：如何合併兩個結果集

Question

我正在使用Oracle數據庫，並且遇到了來自2個結果集的一個結果的問題。

我有表案例

Create table cases (ID varchar(1), date_entered date, sub_category varchar (5)); 

insert into cases (id, date_entered, sub_category) 
values('1', to_date('2012/05/03','yyyy/mm/dd'),'Temp1'); 
insert into cases (id, date_entered, sub_category) 
values('2', to_date('2012/06/01','yyyy/mm/dd'),'Temp2'); 
insert into cases (id, date_entered, sub_category) 
values('3', to_date('2012/03/15','yyyy/mm/dd'),'Temp3'); 
insert into cases (id, date_entered, sub_category) 
values('4', to_date('2012/03/01','yyyy/mm/dd'),'Call1'); 
insert into cases (id, date_entered, sub_category) 
values('5', to_date('2012/03/08','yyyy/mm/dd'),'Call2'); 
insert into cases (id, date_entered, sub_category) 
values('6', to_date('2012/02/20','yyyy/mm/dd'),'Call2'); 

，但需要計算記錄由副類別，分月，其中一個計數包括sub_category：TEMP1，TEMP2，TEMP3 其他數包括sub_category：CALL1，CALL2 ，Call3

我已QUERY1：

With skills 
    AS 
    ( 
      Select sub_category, 
       date_entered, 
       extract(MONTH FROM cases.date_entered) as month_entered, 
       count (*) 
      from cases 
      where 
       SUB_CATEGORY IN('Temp1', 'Temp2', 'Temp3') 


      group by cases.sub_category, cases.date_entered 
      order by to_char(cases.date_entered,'MM') 
    ) 

    select s.month_entered, 
      count(*)as skill_count 
      from skills s 

    group by s.month_entered 
    ORDER BY CAST(s.month_entered AS INTEGER) ASC 

隨r esult：

MONTH_ENTERED SKILL_COUNT 
3    1 
5    1 
6    1 

和查詢2：

With training 
AS 
( 
     Select sub_category, 
      date_entered, 
      extract(MONTH FROM cases.date_entered) as month_entered, 
      count (*) 
     from cases 
     where 
      SUB_CATEGORY IN('Call1', 'Call2', 'Call3') 


     group by cases.sub_category, cases.date_entered 
     order by to_char(cases.date_entered,'MM') 
) 

select t.month_entered, 
     count(*)as training_count 
     from training t 

group by t.month_entered 
ORDER BY CAST(t.month_entered AS INTEGER) ASC 

與結果：

MONTH_ENTERED TRAINING_COUNT 
2    1 
3    2 

，我從這些2次的查詢需要的結果是：

MONTH_ENTERED SKILL_COUNT TRAINING_COUNT 
    2    0   1 
    3    1   2 
    5    1   0 
    6    1   0 

試過工會並離開加入但沒有給我這個結果...

這裏是sqlfiddle例如http://sqlfiddle.com/#!4/504cd/31

請幫幫忙，這是迫切和我卡！ 謝謝提前

GuiGi答案接受。 你能幫助我嗎？或者我需要新的問題？ 如果我想在一年中的所有其他月份顯示零而哪些不在表格中，應該向查詢添加什麼內容？

Answer 1

SELECT 
    EXTRACT(MONTH FROM CASES.DATE_ENTERED) AS MONTH_ENTERED, 
    COUNT (CASE WHEN SUB_CATEGORY IN('Temp1', 'Temp2', 'Temp3') THEN 1 END) SKILL_COUNT, 
    COUNT (CASE WHEN SUB_CATEGORY IN('Call1', 'Call2', 'Call3') THEN 1 END) TRAINING_COUNT 
FROM CASES 
GROUP BY EXTRACT(MONTH FROM DATE_ENTERED) 
ORDER BY MONTH_ENTERED ASC 

Answer 2

我想你可以大大簡化查詢到類似：

 Select extract(MONTH FROM cases.date_entered) as month_entered, 
      sum(case when SUB_CATEGORY IN('Temp1', 'Temp2', 'Temp3') then 1 else 0 end) as Skill_Count, 
      sum(case when SUB_CATEGORY IN('Call1', 'Call2', 'Call3') then 1 else 0 end) as Skill_Count, 
     from cases 
     group by extract(MONTH FROM cases.date_entered) 
     order by extract(MONTH FROM cases.date_entered)