MySQL 对子查询和变量使用 UNION ALL 时出错

Question

我有一个tablecurrency_lkp和一个tableassociate_data associate_data 包含这些列 - 货币、invoice_total 和状态 （未付款或已付款或正在等待） 我可以使用此查询的上半部分 (see MySQL fiddle) 成功 link tables 并提供每种货币的总数。

我还可以为转换为美元的每个状态提供正确的总计（请参阅 query 的下半部分，它产生一行

当我在两半之间使用 UNION ALL 时，它会产生一个结果，但中间三列的数字非常奇怪，但第四列和最后一行的正确结果那一栏。

我认为查询没问题，但如果可以在子查询中使用变量可能会更简洁。任何关于问题所在或如何改进优雅的想法都将不胜感激 - 谢谢

要创建示例数据库：（MySQL 在此下方查询）

    CREATE TABLE IF NOT EXISTS `currency_lkp` (
  `currency_id` int(11) NOT NULL AUTO_INCREMENT,
  `currency` varchar(10) NOT NULL,
  `currency_label` varchar(100) NOT NULL,
  `currency_description` varchar(100) NOT NULL,
  `exchange_rate_USD` float NOT NULL,
  PRIMARY KEY (`currency_id`)
) ENGINE=InnoDB  DEFAULT CHARSET=latin1 AUTO_INCREMENT=6 ;

INSERT INTO `currency_lkp` (`currency_id`, `currency`, 
`currency_label`, `currency_description`, `exchange_rate_USD`)
VALUES
(1, 'GBP', '&pound;', 'Great British Pound (Sterling)', 0.75),
(2, 'Euro', '&euro;', 'Euro currency for the Euro Zone', 0.85),
(3, 'USD', '$', 'United States Dollars', 1),
(4, 'CLP', '$', 'Chilean Pesos', 639.85),
(5, 'INR', '&#8377', 'Indian Rupees', 64.8);

CREATE TABLE IF NOT EXISTS `associate_data` (`associate_data_id`
int(11) NOT NULL AUTO_INCREMENT,
`currency` varchar(10) NOT NULL, 
`status` varchar(20) NOT NULL, 
`invoice_total` float,
 PRIMARY KEY (`associate_data_id`)
) ENGINE=InnoDB  DEFAULT CHARSET=latin1 AUTO_INCREMENT=6 ;

INSERT INTO `associate_data` (`associate_data_id`, `currency`, 
`status`, `invoice_total`)
 VALUES
(1, 'GBP', 'Paid', 200),
(2, 'GBP', 'Unpaid', 300),
(3, 'Euro', 'Paid', 1000),
(4, 'Euro', 'Unpaid', 2000),
(5, 'USD', 'Paid', 1200),
(6, 'USD', 'Unpaid', 1400),
(7, 'GBP', 'WaitingInvoice', 400),
(8, 'Euro', 'WaitingInvoice', 1300),
(9, 'USD', 'WaitingInvoice', 2300),
(10, 'CLP', 'Paid', 100200),
(11, 'CLP', 'Unpaid', 110400),
(12, 'CLP', 'WaitingInvoice', 11200);

MySQL Query in full:
`
(
SELECT cl.currency,
(SELECT SUM(invoice_total) FROM associate_data ad2
WHERE ad2.currency = cl.currency  AND ad2.status = 'Paid') AS Paid,
(SELECT SUM(invoice_total) FROM associate_data ad3
WHERE ad3.currency = cl.currency  AND ad3.status = 'Unpaid') AS Unpaid,
(SELECT SUM(invoice_total) FROM associate_data ad4
WHERE ad4.currency = cl.currency  AND ad4.status = 'WaitingInvoice') AS WaitingInvoice,
(SELECT IFNULL(Unpaid,0) + IFNULL(WaitingInvoice, 0)) AS TotalToPay
FROM currency_lkp cl
)

UNION ALL

(
SELECT 'Total in USD',

FORMAT(
SUM(IFNULL(
(SELECT SUM(invoice_total) FROM associate_data ad5
WHERE ad5.currency = clu.currency AND (ad5.status = 'Paid'))
,0.1)/clu.exchange_rate_USD)
,0) AS TotalUSDPaid,

FORMAT(
SUM(IFNULL(
(SELECT SUM(invoice_total) FROM associate_data ad6
WHERE ad6.currency = clu.currency AND (ad6.status = 'Unpaid'))
,0.1)/clu.exchange_rate_USD)
,0) AS TotalUSDUnpaid,

FORMAT(
SUM(IFNULL(
(SELECT SUM(invoice_total) FROM associate_data ad6
WHERE ad6.currency = clu.currency AND (ad6.status = 'WaitingInvoice'))
,0.1)/clu.exchange_rate_USD)
,0) AS TotalUSDWaitingInvoice,

FORMAT(
SUM(IFNULL(
(SELECT SUM(invoice_total) FROM associate_data ad6
WHERE ad6.currency = clu.currency AND (ad6.status = 'WaitingInvoice' OR ad6.status = 'Unpaid'))
,0.1)/clu.exchange_rate_USD)
,0) AS TotalUSDToPay
FROM currency_lkp clu
)`

Answer 1

您可以通过使用 "conditional aggregates"（聚合函数内部的 case 表达式）来彻底简化您的查询（并提高效率），如下所示：

select
      cu.currency
    , sum(case when ad.status = 'Paid' then invoice_total end) as Paid
    , sum(case when ad.status = 'Unpaid' then invoice_total end) as Unpaid
    , sum(case when ad.status = 'WaitingInvoice' then invoice_total end) as WaitingInvoice_USD
    , FORMAT(sum(case when ad.status = 'Paid' then invoice_total/cu.exchange_rate_USD end),0) as Paid_USD
    , FORMAT(sum(case when ad.status = 'Unpaid' then invoice_total/cu.exchange_rate_USD end),0) as Unpaid_USD
    , FORMAT(sum(case when ad.status = 'WaitingInvoice' then invoice_total/cu.exchange_rate_USD end),0) as WaitingInvoice_USD  
FROM associate_data ad
inner join currency_lkp cu ON ad.currency = cu.currency
group by
      cu.currency
union all
select
      'Total'
    , sum(case when ad.status = 'Paid' then invoice_total end) as Paid
    , sum(case when ad.status = 'Unpaid' then invoice_total end) as Unpaid
    , sum(case when ad.status = 'WaitingInvoice' then invoice_total end) as WaitingInvoice_USD
    , FORMAT(sum(case when ad.status = 'Paid' then invoice_total/cu.exchange_rate_USD end),0) as Paid_USD
    , FORMAT(sum(case when ad.status = 'Unpaid' then invoice_total/cu.exchange_rate_USD end),0) as Unpaid_USD
    , FORMAT(sum(case when ad.status = 'WaitingInvoice' then invoice_total/cu.exchange_rate_USD end),0) as WaitingInvoice_USD  
FROM associate_data ad
inner join currency_lkp cu ON ad.currency = cu.currency
;

该查询产生以下结果：

| currency |   Paid | Unpaid | WaitingInvoice_USD | Paid_USD | Unpaid_USD | WaitingInvoice_USD |
|----------|--------|--------|--------------------|----------|------------|--------------------|
|      CLP | 100200 | 110400 |              11200 |      157 |        173 |                 18 |
|     Euro |   1000 |   2000 |               1300 |    1,176 |      2,353 |              1,529 |
|      GBP |    200 |    300 |                400 |      267 |        400 |                533 |
|      USD |   1200 |   1400 |               2300 |    1,200 |      1,400 |              2,300 |
|    Total | 102600 | 114100 |              15200 |    2,800 |      4,325 |              4,380 |

查看此演示：http://sqlfiddle.com/#!9/b4b5bb/36

您之前查询的某些列中出现乱七八糟的原因是试图合并同一列中的数字和格式化（文本）数据。删除 format( ,0)

参见：http://sqlfiddle.com/#!9/b4b5bb/37

(
SELECT cl.currency,
(SELECT SUM(invoice_total) FROM associate_data ad2
WHERE ad2.currency = cl.currency  AND ad2.status = 'Paid') AS Paid,
(SELECT SUM(invoice_total) FROM associate_data ad3
WHERE ad3.currency = cl.currency  AND ad3.status = 'Unpaid') AS Unpaid,
(SELECT SUM(invoice_total) FROM associate_data ad4
WHERE ad4.currency = cl.currency  AND ad4.status = 'WaitingInvoice') AS WaitingInvoice,
(SELECT IFNULL(Unpaid,0) + IFNULL(WaitingInvoice, 0)) AS TotalToPay
FROM currency_lkp cl
)
UNION ALL
(
SELECT 'Total in USD',


SUM(IFNULL(
(
  SELECT SUM(invoice_total) FROM associate_data ad5
WHERE ad5.currency = clu.currency AND (ad5.status = 'Paid')
),0.1)/clu.exchange_rate_USD) 
  AS TotalUSDPaid,


SUM(IFNULL(
(SELECT SUM(invoice_total) FROM associate_data ad6
WHERE ad6.currency = clu.currency AND (ad6.status = 'Unpaid'))
,0.1)/clu.exchange_rate_USD)
 AS TotalUSDUnpaid,


SUM(IFNULL(
(SELECT SUM(invoice_total) FROM associate_data ad6
WHERE ad6.currency = clu.currency AND (ad6.status = 'WaitingInvoice'))
,0.1)/clu.exchange_rate_USD)
 AS TotalUSDWaitingInvoice,


SUM(IFNULL(
(SELECT SUM(invoice_total) FROM associate_data ad6
WHERE ad6.currency = clu.currency AND (ad6.status = 'WaitingInvoice' OR ad6.status = 'Unpaid'))
,0.1)/clu.exchange_rate_USD)
 AS TotalUSDToPay
FROM currency_lkp clu
)

查询的结果是：

|     currency |               Paid |           Unpaid |    WaitingInvoice |        TotalToPay |
|--------------|--------------------|------------------|-------------------|-------------------|
|          GBP |                200 |              300 |               400 |               700 |
|         Euro |               1000 |             2000 |              1300 |              3300 |
|          USD |               1200 |             1400 |              2300 |              3700 |
|          CLP |             100200 |           110400 |             11200 |            121600 |
|          INR |             (null) |           (null) |            (null) |                 0 |
| Total in USD | 2799.7379740260294 | 4325.48309943104 | 4380.250701542091 | 8705.732257763328 |

注意：我没有尝试更正任何查询算法，但显然其中一个是错误的

MySQL 对子查询和变量使用 UNION ALL 时出错

MySQL errors using UNION ALL with subqueries and variables

mysql

variables

subquery

union-all