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两列结合条件mysql

2016-06-21 95 views
3

我想结合2个不同列的条件来查询。这是我的原始查询。你可以在sqlfiddle.com中测试它。两列结合条件mysql

-- creating database first for test data 
create table attendance(Id int, DateTime datetime, Door char(20)); 
INSERT INTO attendance VALUES 
( 1, '2016-01-01 08:00:00', 'In'), 
( 2, '2016-01-01 09:00:00', 'Out'), 
( 3, '2016-01-01 09:15:00', 'In'), 
( 4, '2016-01-01 09:30:00', 'In'), 
( 5, '2016-01-01 10:00:00', 'Out'), 
( 6, '2016-01-01 15:00:00', 'In'); 

SELECT * FROM attendance; 
SELECT 
@id:[email protected]+1 Id, 
MAX(IF(Door = 'In', DateTime, NULL)) `Check In`, 
MAX(IF(Door = 'Out', DateTime, NULL)) `Check Out` 
FROM 
(SELECT 
*, 
CASE 
    WHEN 
     (Door != 'Out' AND @last_door = 'Out') 
    THEN @group_num:[email protected]_num+1 
    ELSE @group_num END door_group, 
    @last_door:=Door 
FROM attendance 
JOIN (SELECT @group_num:=1,@last_door := NULL) a 
) t JOIN (SELECT @id:=0) b 
GROUP BY t.door_group 
HAVING SUM(Door = 'In') > 0 AND SUM(Door = 'Out') > 0; 

//output 
+------+---------------------+---------------------+ 
| Id | Check In   | Check Out   | 
+------+---------------------+---------------------+ 
| 1 | 2016-01-01 08:00:00 | 2016-01-01 09:00:00 | 
| 2 | 2016-01-01 09:30:00 | 2016-01-01 10:00:00 | 
+------+---------------------+---------------------+

从上面的查询中，我想再添加一列。

-- creating database first for test data 
create table attendance(Id int, DateTime datetime, Door char(20), Active_door char(20)); 
INSERT INTO attendance VALUES 
( 1, '2016-01-01 08:00:00', 'In', ''), 
( 2, '2016-01-01 09:00:00', 'Out', ''), 
( 3, '2016-01-01 09:15:00', 'In', ''), 
( 4, '2016-01-01 09:30:00', 'In', ''), 
( 5, '2016-01-01 09:35:00', '', 'On'), 
( 6, '2016-01-01 10:00:00', 'Out', ''), 
( 7, '2016-01-01 16:00:00', '', 'Off');

这是我对我的查询所做的更改，但它不起作用。

SELECT * FROM attendance; 
SELECT 
@id:[email protected]+1 Id, 
MAX(IF(Door = 'In' OR Active_door = "On", DateTime, NULL)) `Check In`, 
MAX(IF(Door = 'Out' OR Active_door = "Off", DateTime, NULL)) `Check Out` 
FROM 
(SELECT 
*, 
CASE 
    WHEN 
     ((Door != 'Out' OR Active_door != "Off") AND (@last_door = 'Out' OR @last_door = 'Off')) 
    THEN @group_num:[email protected]_num+1 
    ELSE @group_num END door_group, 
    @last_door:=Door 
FROM attendance 
JOIN (SELECT @group_num:=1,@last_door := NULL) a 
) t JOIN (SELECT @id:=0) b 
GROUP BY t.door_group 
HAVING SUM(Door = 'In') > 0 OR SUM(Active_door = 'On') > 0 AND SUM(Door = 'Out') > 0 OR SUM(Active_door = 'Off') > 0; 

//output 
+------+---------------------+---------------------+ 
| Id | Check In   | Check Out   | 
+------+---------------------+---------------------+ 
| 1 | 2016-01-01 08:00:00 | 2016-01-01 09:00:00 | 
| 2 | 2016-01-01 09:35:00 | 2016-01-01 10:00:00 | 
| 3 | NULL    | 2016-01-01 16:00:00 | 
+------+---------------------+---------------------+ 

//my desire output 
+------+---------------------+---------------------+ 
| Id | Check In   | Check Out   | 
+------+---------------------+---------------------+ 
| 1 | 2016-01-01 08:00:00 | 2016-01-01 09:00:00 | 
| 2 | 2016-01-01 09:35:00 | 2016-01-01 16:00:00 | 
+------+---------------------+---------------------+

请帮助我们如何获得所需的输出。我想从两栏中获得最后一笔，最后一笔。先谢谢你。

来源

2016-06-21 EDDY

+3

我upvoting将此作为一个例子每mysql的问题应该如何被写入保存帮助手动执行创建和数据加载。不这样做（无论是在问题中还是在sqlfiddle中）都会导致很多人通过你的问题。谢谢。 – Drew

+0

从第6行到第7行，添加第3个'door-group'（导致您的第3行），因为last_state值是out（从第6行开始），实际的门值是empty '（在第7行），所以'Door！='Out OR ...'是真的。这取决于你的逻辑（何时创建一个新组）如何改变这种状况 - 我假设你需要检查'！='''或类似的东西。你可能想在'OR @last_door ='Off''检查你的代码，因为据我所知，这不会是真的（你可能打算使用另一个变量，比如'@ last_active_door'或者设置'@last_door： ='也取决于'active_door' – Solarflare

+0

我忘了添加：为你的内部查询添加一个命令，例如'order by id'，或'order by DateTime'使它可靠。对你而言，你可能是幸运的您的数据已经由DateTime订购（尽管这可能对您没有任何问题） – Solarflare

回答

1

这努力保持解决方案易于维护，没有完成最终查询所有在一个镜头，这将几乎加倍它的大小（在我心中）。这是因为结果需要匹配，并在匹配的In和Out事件的一行中表示。最后，我使用了几张工作表。它在存储过程中实现。

存储过程使用几个带有cross join的变量。将交叉连接想象为初始化变量的机制。变量保持安全，所以我相信，这个document的精神经常在变量查询中引用。引用的重要部分是安全处理一行中的变量，强制它们在使用它们的其他列之前被设置。这是通过greatest()和least()函数实现的，这些函数的优先级高于不使用这些函数的变量。请注意，coalesce()经常用于相同的目的。如果他们的使用看起来很奇怪，比如把已知的数字中的最大数字大于0或0，那么这是故意的。慎重强制设置变量的优先顺序。

查询中命名为dummy2等的列是未使用输出的列，但它们用于在greatest()或其他内部设置变量。这是上面提到的。 7777之类的输出是第3个插槽中的占位符，因为所用的if()需要一些值。所以忽略这一切。

我已经包含了代码的几个屏幕截图，因为它逐层进行以帮助您可视化输出。以及这些迭代的发展如何慢慢地进入下一阶段，以扩展先前的发展。

我确定我的同事可以在一个查询中对此进行改进。我本可以用这种方式完成它。但我相信这会导致一个混乱的混乱，如果感动就会破裂。

模式：

create table attendance2(Id int, DateTime datetime, Door char(20), Active_door char(20)); 
INSERT INTO attendance2 VALUES 
( 1, '2016-01-01 08:00:00', 'In', ''), 
( 2, '2016-01-01 09:00:00', 'Out', ''), 
( 3, '2016-01-01 09:15:00', 'In', ''), 
( 4, '2016-01-01 09:30:00', 'In', ''), 
( 5, '2016-01-01 09:35:00', '', 'On'), 
( 6, '2016-01-01 10:00:00', 'Out', ''), 
( 7, '2016-01-01 16:00:00', '', 'Off'); 

drop table if exists oneLinersDetail; 
create table oneLinersDetail 
( -- architect this depending on multi-user concurrency 
    id int not null, 
    dt datetime not null, 
    door int not null, 
    grpIn int not null, 
    grpInSeq int not null, 
    grpOut int not null, 
    grpOutSeq int not null 
); 

drop table if exists oneLinersSummary; 
create table oneLinersSummary 
( -- architect this depending on multi-user concurrency 
    id int not null, 
    grpInSeq int null, 
    grpOutSeq int null, 
    checkIn datetime null, -- we are hoping in the end it is not null 
    checkOut datetime null -- ditto 
);

存储过程：

DROP PROCEDURE IF EXISTS fetchOneLiners; 
DELIMITER $$ 
CREATE PROCEDURE fetchOneLiners() 
BEGIN 
    truncate table oneLinersDetail; -- architect this depending on multi-user concurrency 

    insert oneLinersDetail(id,dt,door,grpIn,grpInSeq,grpOut,grpOutSeq) 
    select id,dt,door,grpIn,grpInSeq,grpOut,grpOutSeq 
    from 
    ( select id,dt,door, 
     if(@lastEvt!=door and door=1, 
      greatest(@grpIn:[email protected]+1,0), 
      7777) as dummy2, -- this output column we don't care about (we care about the variable being set) 
     if(@lastEvt!=door and door=2, 
      greatest(@grpOut:[email protected]+1,0), 
      7777) as dummy3, -- this output column we don't care about (we care about the variable being set) 
     if (@lastEvt!=door,greatest(@flip:=1,0),least(@flip:=0,1)) as flip, 
     if (door=1 and @flip=1,least(@grpOutSeq:=0,1),7777) as dummy4, 
     if (door=1 and @flip=1,greatest(@grpInSeq:=1,0),7777) as dummy5, 
     if (door=1 and @flip!=1,greatest(@grpInSeq:[email protected]+1,0),7777) as dummy6, 
     if (door=2 and @flip=1,least(@grpInSeq:=0,1),7777) as dummy7, 
     if (door=2 and @flip=1,greatest(@grpOutSeq:=1,0),7777) as dummy8, 
     if (door=2 and @flip!=1,greatest(@grpOutSeq:[email protected]+1,0),7777) as dummy9, 
     @grpIn as grpIn, 
     @grpInSeq as grpInSeq, 
     @grpOut as grpOut, 
     @grpOutSeq as grpOutSeq, 
     @lastEvt:=door as lastEvt 
     from 
     ( select id,`datetime` as dt, 
      CASE 
       WHEN Door='in' or Active_door='on' THEN 1 
       ELSE 2 
      END as door 
      from attendance2 
      order by id 
     ) xD1 -- derived table #1 
     cross join (select @grpIn:=0,@grpInSeq:=0,@grpOut:=0,@grpOutSeq:=0,@lastEvt:=-1,@flip:=0) xParams 
     order by id 
    ) xD2 -- derived table #2 
    order by id; 
    -- select * from oneLinersDetail; 

    truncate table oneLinersSummary; -- architect this depending on multi-user concurrency 

    insert oneLinersSummary (id,grpInSeq,grpOutSeq,checkIn,checkOut) 
    select distinct grpIn,null,null,null,null 
    from oneLinersDetail 
    order by grpIn; 

    -- select * from oneLinersSummary; 

    update oneLinersSummary ols 
    join 
    ( select grpIn,max(grpInSeq) m 
     from oneLinersDetail 
     where door=1 
     group by grpIn 
    ) d1 
    on d1.grpIn=ols.id 
    set ols.grpInSeq=d1.m; 

    -- select * from oneLinersSummary; 

    update oneLinersSummary ols 
    join 
    ( select grpOut,max(grpOutSeq) m 
     from oneLinersDetail 
     where door=2 
     group by grpOut 
    ) d1 
    on d1.grpOut=ols.id 
    set ols.grpOutSeq=d1.m; 

    -- select * from oneLinersSummary; 

    update oneLinersSummary ols 
    join oneLinersDetail old 
    on old.door=1 and old.grpIn=ols.id and old.grpInSeq=ols.grpInSeq 
    set ols.checkIn=old.dt; 

    -- select * from oneLinersSummary; 

    update oneLinersSummary ols 
    join oneLinersDetail old 
    on old.door=2 and old.grpOut=ols.id and old.grpOutSeq=ols.grpOutSeq 
    set ols.checkOut=old.dt; 

    -- select * from oneLinersSummary; 

    -- dump out the results 
    select id,checkIn,checkOut 
    from oneLinersSummary 
    order by id; 
    -- rows are left in those two tables (oneLinersDetail,oneLinersSummary) 
END$$ 
DELIMITER ;

测试：

call fetchOneLiners(); 
+----+---------------------+---------------------+ 
| id | checkIn    | checkOut   | 
+----+---------------------+---------------------+ 
| 1 | 2016-01-01 08:00:00 | 2016-01-01 09:00:00 | 
| 2 | 2016-01-01 09:35:00 | 2016-01-01 16:00:00 | 
+----+---------------------+---------------------+

这是答案的结尾。以下内容是开发人员对导致完成存储过程的步骤的可视化。

开发的版本，直到最后。希望这有助于可视化，而不是仅仅丢弃中等大小的混淆代码块。

步骤A

enter image description here

步骤B

enter image description here

步骤B输出

enter image description here

步骤C

enter image description here

步骤C输出

enter image description here

来源

2016-06-21 11:59:51 Drew

+0

我尝试“保持足够的独立”，但似乎无法获得预期的结果。为什么我不能得到值“2016-01-01 16:00:00”的列“Active_door”的值？再次检查我想要的输出 – EDDY

+0

可能最好解释它对我来说，我们可以将其总结为一个编辑，我在这个叫做[Campaigns]的房间里（http://chat.stackoverflow.com/rooms/95290 /广告系列） – Drew

+0

哇..这是很多来自你@Drew的作品。我仍然深入你的代码，让自己了解整个过程。非常感谢您为此案所做的全部努力！如果我不明白在查询中使用的某个术语，会再次通知您。 :) – EDDY

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