提取一行特定场景

Question

我有以下细节

EMP_NAME  TEST_RESULT RUN_DATE 
---------------------------------------------- 
John   Pass 12-FEB-2013 18:03:55 
Albert   Fail 12-FEB-2013 18:24:29 
Chris   Pass 12-FEB-2013 18:24:28 
John   Fail 12-FEB-2013 19:32:35 
Chris   Pass 12-FEB-2013 19:32:35 
Steve   Pass 12-FEB-2013 20:04:35 

现在我需要具有独特的名称和TEST_RESULT提取行的表。但是，如果员工同时具有合格和不合格的结果，则测试结果应该只有“失败”结果。查询的结果应该是

EMP_NAME  TEST_RESULT RUN_DATE 
---------------------------------------------- 
Albert   Fail 12-FEB-2013 18:24:29 
Chris   Pass 12-FEB-2013 18:24:28 
John   Fail 12-FEB-2013 19:32:35 
Steve   Pass 12-FEB-2013 20:04:35 

所有我关心的只有一个员工姓名，如果有两个结果及格和不及格该员工，告诉我只有失败的记录，我不计较时间。如果一个员工有两个结果作为“合格”和“合格”，我仍然需要一个记录，我不在乎时间。

Answer 1


Select emp_name, test_result, run_date
from (
select emp_name, test_result, run_date,
row_number() over (partition by emp_name
order by test_result, run_date) rn
from
T1)
where rn=1

Answer 2

这样的事情可能会奏效。

select emp_name, test_result, run_date 
from YourTable 
where test_result = 'Fail' 
union 
select emp_name, test_result, run_date 
from YourTable 
where test_result = 'Pass' 
and emp_name in 
(select emp_name 
from YourTable 
where TestResult = 'Pass' 
minus 
select emp_name 
from YourTable 
where TestResult = 'Fail' 
) 

Answer 3

SELECT EMP_NAME, TEST_RESULT, RUN_DATE 
FROM (
    SELECT ROW_NUMBER() OVER (PARTITION BY t1.EMP_NAME ORDER BY RUN_DATE) AS RowNumber, 
     t1.EMP_NAME, TEST_RESULT, RUN_DATE 
    FROM MyTable t1 
    LEFT JOIN 
    (SELECT DISTINCT EMP_NAME 
    FROM MyTable 
    WHERE TEST_RESULT = 'Fail' 
) AS EMP_With_Failure ON t1.EMP_NAME = EMP_With_Failure.EMP_Name 
    WHERE t1.TEST_RESULT = 'Fail' OR EMP_With_Failure.EMP_NAME IS NULL) t 
WHERE RowNumber = 1 

这个查询会过滤掉任何成功的记录为有故障的任何用户，您仍然需要过滤结果集，让每用户