Question

我有一个具有以下架构的表：

DATA | CAUSE_1 | TIME_1 | CAUSE_2 | TIME_2 | CAUSE_3 | TIME_3

CAUSE.*字段（VarChar）不能包含任何字符串，如果是，则字段TIME.*为0。

我正在尝试创建一个查询，但遗憾的是没有成功，我将以这种形式显示结果：

CAUSE | TOT_TIME | N_RIPET_CAUSE,

其中：

在CAUSE中，我列出了CAUSE_1 ... CAUSE_3，
TOT_TIME中TIME_1 ... TIME_3，
在N_RIPET_CAUSE中CAUSE的重复次数。

我希望我解释过。

Answer 1

试试这个

 SELECT DATA ,CAUSE , TOT_TIME , N_RIPET_CAUSE
 FROM ( select DATA, CONCAT(`CAUSE_1`,' ',`CAUSE_2`, ' ', `CAUSE_3`) as CAUSE ,
 sum(`TIME_1` + `TIME_2` +`TIME_3`) as TOT_TIME ,
 (count(`CAUSE_1`)+count(`CAUSE_2`)+count(`CAUSE_3`)) as N_RIPET_CAUSE
 FROM your_table
 group by DATA
 ) t

SEE SQLFIDDLE DEMO

EDIT。

试试这个

     ( select DATA , `CAUSE_1` as CAUSE ,
     sum(`TIME_1` + `TIME_2` +`TIME_3`) as TOT_TIME ,
     (count(`CAUSE_1`)+count(`CAUSE_2`)+count(`CAUSE_3`)) as N_RIPET_CAUSE
     FROM Table1 
    group by DATA)
  union all
    (select DATA , `CAUSE_2` as CAUSE ,
    sum(`TIME_1` + `TIME_2` +`TIME_3`) as TOT_TIME ,
    (count(`CAUSE_1`)+count(`CAUSE_2`)+count(`CAUSE_3`)) as N_RIPET_CAUSE
    FROM Table1
    group by DATA   )
  union all

    (select DATA , `CAUSE_3` as CAUSE ,
    sum(`TIME_1` + `TIME_2` +`TIME_3`) as TOT_TIME ,
    (count(`CAUSE_1`)+count(`CAUSE_2`)+count(`CAUSE_3`)) as N_RIPET_CAUSE
    FROM Table1
    group by DATA   )

SQL DEMO HERE

修改

根据您的需要尝试

select cause, sum(time) Tot_time, count(cause) N_Ripet_Cause from( select cause_1 as cause, time_1 as time from Table1 union all select cause_2 as cause, time_2 as time from Table1 union all select cause_3 as cause, time_3 as time from Table1 ) t group by cause

DEMO SQL FIDDLE

Answer 2

您可以从联合选择中进行选择：

select * from
(
    select cause_1 as cause, time_1 as time from tableName
    union
    select cause_2 as cause, time_2 as time from tableName
    union
    select cause_3 as cause, time_3 as time from tableName
) as joinedValues

然后你可以从那个选择中执行任何操作。像每个条款的数量一样：

select cause, count(cause) from
(
...
) as joinedValues
group by cause

Answer 3

杰克已经出现了 - 你的桌面结构中有太多可能冗余的单元格。使用关系来消除这种情况。

的数据表 的 dID |数据

的 instancesTable 的 ID | dID |原因| TIME

然后在两个表上使用NATURAL JOIN来提取信息;

SELECT * FROM DataTable NATURAL JOIN instancesTable WHERE dID=? LIMIT 3

此查询将返回第一个表中“数据”ID的原因和时间列表。

编辑：*可以使用dID上的 SUM（CAUSE）找到N_RIPET_CAUSE *。

在MySql中使用UNION的SUM，COUNT

3 个答案: