INSERT SELECT上的重複不更新

Question

短

1. 我想SUM基於CRITERIA X和插入TABLE_B.total_x
2. 我想SUM列在TABLE_A基於CRITERIA Y並插入到TABLE_A列TABLE_B.total_y
3. 問題：步驟2不更新TABLE_B.total_y

LONG

TABLE_A：數據

| year | month | type | total | 
--------------------------------------- 
| 2013 | 11 | down | 100 | 
| 2013 | 11 | down | 50 | 
| 2013 | 11 | up | 60 | 
| 2013 | 10 | down | 200 | 
| 2013 | 10 | up | 15 | 
| 2013 | 10 | up | 9  | 

表-B：結構

CREATE TABLE `TABLE_B` (
    `year` INT(4) NULL DEFAULT NULL, 
    `month` INT(2) UNSIGNED ZEROFILL NULL DEFAULT NULL, 
    `total_x` INT(10) NULL DEFAULT NULL, 
    `total_y` INT(10) NULL DEFAULT NULL, 
    UNIQUE INDEX `unique` (`year`, `month`) 
) 

SQL：CRITERIA_X

INSERT INTO TABLE_B (
`year`, `month`, `total_x` 
) 
SELECT 
    t.`year`, t.`month`, 
    SUM(t.`total`) as total_x 
FROM TABLE_A t 
WHERE 
    t.`type` = 'down' 
GROUP BY 
    t.`year`, t.`month` 
ON DUPLICATE KEY UPDATE 
    `total_x` = total_x 
; 

SQL：CRITERIA_Y

INSERT INTO TABLE_B (
`year`, `month`, `total_y` 
) 
SELECT 
    t.`year`, t.`month`, 
    SUM(t.`total`) as total_y 
FROM TABLE_A t 
WHERE 
    t.`type` = 'up' 
GROUP BY 
    t.`year`, t.`month` 
ON DUPLICATE KEY UPDATE 
    `total_y` = total_y 
; 

第二SQL（CRITERIA_Y）如預期不更新total_y。 爲什麼？

Answer 1

我會做另一種方式

insert into TABLE_B (year, month, total_x, total_y) 
select year, month 
    , sum (case [type] when 'down' then [total] else 0 end) [total_x] 
    , sum (case [type] when 'up' then [total] else 0 end) [total_y] 
from TABLE_A 
group by [year], [month] 

或者使用兩個子查詢的方式是

insert into TABLE_B (year, month, total_x, total_y) 
select coalesce(t1.year, t2.year) year 
    , coalesce(t1.month, t2.month) month 
    , t1.total_x total_x 
    , t2.total_y total_y 
from (select year, month, sum(total) total_x 
     from TABLE_A where [type]='down') t1 
full outer join 
    (select year, month, sum(total) total_y 
     from TABLE_A where [type]='up') t2 
    on t1.year = t2.year and t1.month = t2.month 

或者使用工會在INSERT

insert into TABLE_B (year, month, total_x, total_y) 
select year, month, sum(total_x), sum(total_y) 
from ( 
    select year, month, sum(total) total_x, 0 total_y 
    from TABLE_A where [type]='down' 
    group by year, month 
    union 
    select year, month, 0 total_x, sum(total) total_y 
    from TABLE_A where [type]='up' 
    group by year, month) t 
group by year, month 

閱讀規格... ON DUPLICATE KEY UPDATE，我注意到這個：

如果...匹配多行，則只更新一行。通常，您應該儘量避免在具有多個唯一索引的表上使用ON DUPLICATE KEY UPDATE子句。

因此，使用複合鍵的語法很麻煩，我個人會避免使用它。