Question

我的任务估计需要几个小时。花费的时间减去估计应该会花费时间。

员工表

CREATE TABLE sign
    (signid varchar(3), signname varchar(30));    
INSERT INTO sign
    (signid, signname)
VALUES
    ('AA', 'Adam'),
    ('BB', 'Bert'),
    ('CC', 'Cecil'),
    ('DD', 'David')

任务表

CREATE TABLE task
    (taskid int4, taskdate date, tasksign varchar(3), taskhr numeric(10,2));

INSERT INTO task
    (taskid, taskdate, tasksign, taskhr)
VALUES
    (1,'2016-01-01','AA',10),
    (2,'2016-02-01','BB',10),
    (3,'2016-01-15','BB',10),
    (4,'2016-03-01','BB',10),
    (5,'2016-01-03','CC',10)

时间表表格

CREATE TABLE hr
    (hrid int4, hrsign varchar(3), hrtask int4, hrqty numeric(10,2));

INSERT INTO hr
    (hrid, hrsign, hrtask, hrqty)
VALUES
    (1,'AA',1,1.1),
    (2,'BB',2,1.2),
    (3,'CC',5,2.3),
    (4,'CC',5,5)

我试图从估计的时间中减去花费的时间的简单查询给出了错误的答案：

SELECT    signid,signname,to_char(taskdate, 'iyyy-iw'),sum(taskhr),sum(hrqty)
FROM      sign
LEFT JOIN task ON tasksign=signid
LEFT JOIN hr ON taskid=hrtask
GROUP BY  1,2,3
ORDER BY  2,3

答案是：

id  name    week     task   hr
AA  Adam    2015-53  10     1,1000
BB  Bert    2016-02  10     NULL
BB  Bert    2016-05  10     1,2000
BB  Bert    2016-09  10     NULL
CC  Cecil   2015-53  20     7,3000
DD  David   NULL     NULL   NULL

任务时间似乎重复。它应该是这样的：

id  name    week     task   hr
AA  Adam    2015-53  10     1,1000
BB  Bert    2016-02  10     NULL
BB  Bert    2016-05  10     1,2000
BB  Bert    2016-09  10     NULL
CC  Cecil   2015-53  10     7,3000
DD  David   NULL     NULL   NULL

如何提出计算正确的查询？

“小提琴”

http://rextester.com/UOO16020

Answer 1

加入hr表将task表行相乘。加入前汇总hr：

select signid, signname, to_char(taskdate, 'iyyy-iw'), sum(taskhr), sum(hrqty)
from
    sign
    left join
    task on tasksign = signid
    left join (
        select hrtask, sum(hrqty) as hrqty
        from hr
        group by 1
    )
    hr on taskid = hrtask
group by  1,2,3
order by  2,3
;
 signid | signname | to_char |  sum  | sum  
--------+----------+---------+-------+------
 AA     | Adam     | 2015-53 | 10.00 | 1.10
 BB     | Bert     | 2016-02 | 10.00 |     
 BB     | Bert     | 2016-05 | 10.00 | 1.20
 BB     | Bert     | 2016-09 | 10.00 |     
 CC     | Cecil    | 2015-53 | 10.00 | 7.30
 DD     | David    |         |       |

估计时间减去花费的时间错误结果 - postgresql

1 个答案: