从MySQL中的两个表中检索数据

Question

我试图从两个表中获取日期，但问题是他们正在返回多个行的个人ID。 我有表像这样： -

Transaction 
----------- 
tid|startdate|enddate|status 
100|2-9-2015|2-9-2015|success 
200|1-9-2015|1-9-2015|failed 
300|31-8-2015|31-8-2015|success 

Test_Details 
------------ 
id|tid|test_name|test_status 
1|100|Test1|yes 
2|100|Tes2|no 
3|100|Test3|yes 
4|200|Test1|no 
5|200|Tes2|no 
6|200|Test3|yes 
7|300|Test1|yes 
8|300|Tes2|no 
9|300|Test3|no 

期望的结果： -

tid|startdate|enddate|status|Test1|Test2|Test3 
100|2-9-2015|2-9-2015|success|yes|no|yes 
200|1-9-2015|1-9-2015|failed|no|no|yes 
300|31-8-2015|31-8-2015|success|yes|no|no 

我使用这个查询： -

select distinct ts.tid as tid, ts.startdate as startdate, 
ts.enddate as enddate, ts.status as status, 
CASE WHEN (td.test_name='Test1') THEN test_status END as Test1, 
CASE WHEN (td.test_name='Test2') THEN test_status END as Test2, 
CASE WHEN (td.test_name='Test3') THEN test_status END as Test3 
from transation ts, test_details td where ts.tid =td.id 

但是我却越来越多行。 这里是SQLFiddle演示

Answer 1

您可以使用GROUP BY查询，例如与GROUP_CONCAT聚合函数：

SELECT 
    ts.tid as tid, 
    ts.startdate as startdate, 
    ts.enddate as enddate, 
    ts.status as status, 
    GROUP_CONCAT(test_status ORDER BY td.test) 
FROM 
    transation ts LEFT JOIN test_details td ON ts.tid =td.id 
GROUP BY 
    ts.tid, 
    ts.startdate, 
    ts.enddate, 
    ts.status 

或此查询，如果你想在不同的列状态：

SELECT 
    ts.tid as tid, 
    ts.startdate as startdate, 
    ts.enddate as enddate, 
    ts.status as status, 
    MAX(CASE WHEN (td.test_name='Test1') THEN test_status END) as Test1, 
    MAX(CASE WHEN (td.test_name='Test2') THEN test_status END) as Test2, 
    MAX(CASE WHEN (td.test_name='Test3') THEN test_status END) as Test3 
FROM 
    transation ts LEFT JOIN test_details td ON ts.tid =td.id 
GROUP BY 
    ts.tid, 
    ts.startdate, 
    ts.enddate, 
    ts.status 

Answer 2

只要test_details不是临时表，您可以执行以下操作：

SELECT ts.tid, ts.startdate, ts.enddate, ts.status, 
    t1.test_status Test1, 
    t2.test_status Test2, 
    t3.test_status Test3 
FROM transaction ts 
    LEFT JOIN test_details t1 ON (t1.tid=ts.tid AND t1.test_name='Test1') 
    LEFT JOIN test_details t2 ON (t2.tid=ts.tid AND t2.test_name='Test2') 
    LEFT JOIN test_details t3 ON (t3.tid=ts.tid AND t3.test_name='Test3'); 

这是假设transaction.tid是唯一的，并且test_details中的（tid，test_name）对是唯一的。

编辑：在回答OP的评论“这是工作，但它是在大分贝慢”我建议添加索引到test_details.tid和test_details.test_name：

ALTER TABLE test_details ADD INDEX (tid); 
ALTER TABLE test_details ADD INDEX (test_name); 

而且，如果所有的三个测试已知的所有交易存在，您可能需要使用，而不是JOINLEFT JOIN

SELECT ts.tid, ts.startdate, ts.enddate, ts.status, 
    t1.test_status Test1, 
    t2.test_status Test2, 
    t3.test_status Test3 
FROM transaction ts 
    JOIN test_details t1 ON (t1.tid=ts.tid AND t1.test_name='Test1') 
    JOIN test_details t2 ON (t2.tid=ts.tid AND t2.test_name='Test2') 
    JOIN test_details t3 ON (t3.tid=ts.tid AND t3.test_name='Test3'); 

Answer 3

select 
    ts.tid as tid, 
    ts.startdate as startdate, 
    ts.enddate as enddate, 
    ts.status as status, 
    group_concat(test1) test1, 
    group_concat(test2) test2, 
    group_concat(test3) test3 
    from 
    (select 
     ts.tid as tid, 
     ts.status as status, 
     CASE WHEN (td.test_name='Test1') THEN test_status END as Test1, 
     CASE WHEN (td.test_name='Tes2') THEN test_status END as Test2, 
     CASE WHEN (td.test_name='Test3') THEN test_status END as Test3 
     from 
     transation ts 
     join 
     test_details td 
     on ts.tid=td.tid 
    ) t 
group by tid 

Answer 4

您可以只用保留制度

select distinct ts.tid as tid, ts.startdate as startdate, 
ts.enddate as enddate, ts.status as status, 
CASE WHEN (td.test_name='Test1') THEN test_status END as Test1, 
CASE WHEN (td.test_name='Test2') THEN test_status END as Test2, 
CASE WHEN (td.test_name='Test3') THEN test_status END as Test3 
from transation ts, test_details td 
where ts.tid =td.id 
group by ts.tid;