SQL Server案例

Question

关于如何获得每个案例ID只有非空值的任何建议？

这里是SQL语句

SELECT 
    c.record_id, 
    CASE WHEN a.Question_Key = 'AA1.DQ6.EF10' THEN (b.selection_value) end as Q1, 
    CASE WHEN a.Question_Key = 'AA1.DQ6.EF11' THEN (b.selection_value) end as Q2, 
    CASE WHEN a.Question_Key = 'AA1.DQ6.EF12' THEN (b.selection_value) end as Q3, 
    CASE WHEN a.Question_Key = 'AA1.DQ6.EF13' THEN (b.selection_value) end as Q4, 
    CASE WHEN a.Question_Key = 'AA1.DQ6.EF14' THEN (b.selection_value) end as Q5, 
    CASE WHEN a.Question_Key = 'AA1.DQ6.EF15' THEN (b.selection_value) end as Q6, 
    CASE WHEN a.Question_Key = 'AA1.DQ6.EF16' THEN (b.selection_value) end as Q7 
FROM 
    COL_CASE_Case c 
INNER JOIN 
    COL_SURV_Survey s ON c.Case_Key = s.Parent_Record_Key 
INNER JOIN 
    COL_SURV_Survey_Answers b ON s.Survey_Key = b.Survey_Key 
INNER JOIN 
    COL_SURV_Survey_Questions a ON b.Question_Key = a.Question_Key 
WHERE 
    a.Question_Type = 0 AND c.record_id = 'CASE-0002999' 

我recieving输出是4行的每一种情况下。请参阅附件图片。 enter image description here

Answer 1

您可以像使用MAX()聚集和GROUP BY：

SELECT c.record_id, 
     MAX(CASE WHEN a.Question_Key = 'AA1.DQ6.EF10' THEN (b.selection_value) end) as Q1, 
     MAX(CASE WHEN a.Question_Key = 'AA1.DQ6.EF11' THEN (b.selection_value) end) as Q2, 
     MAX(CASE WHEN a.Question_Key = 'AA1.DQ6.EF12' THEN (b.selection_value) end) as Q3, 
     MAX(CASE WHEN a.Question_Key = 'AA1.DQ6.EF13' THEN (b.selection_value) end) as Q4, 
     MAX(CASE WHEN a.Question_Key = 'AA1.DQ6.EF14' THEN (b.selection_value) end) as Q5, 
     MAX(CASE WHEN a.Question_Key = 'AA1.DQ6.EF15' THEN (b.selection_value) end) as Q6, 
     MAX(CASE WHEN a.Question_Key = 'AA1.DQ6.EF16' THEN (b.selection_value) end) as Q7 
FROM COL_CASE_Case c inner join COL_SURV_Survey s on c.Case_Key = s.Parent_Record_Key 
inner join COL_SURV_Survey_Answers b on s.Survey_Key = b.Survey_Key 
inner join COL_SURV_Survey_Questions a on b.Question_Key = a.Question_Key 
WHERE a.Question_Type = 0 and c.record_id = 'CASE-0002999' 
GROUP BY c.record_id