按初始调查回复过滤回复

Question

我有一个表需要被同一个表中的其他响应过滤。我使用以下有效的脚本，但是当“Customer.customer_id”（有时有）重复时，结果会出现偏差。我的问题是是否有更好的方法来重写此代码以避免这种情况，因此它只从“客户”表中选择不同的结果？

下面的示例表应该只返回“两个”响应，因为 customer_id '10' 有重复条目（基于下面的查询）

示例表：

[res_id]  [question_id]  [customer_id]  [survey_id]  [res_answer]
  1            20             10           155          male
  1            20             11           155          male
  1            20             10           155          male
  1            20             12           155          female

当前查询：

  SELECT
  Responses.res_id AS responseID
     ,Responses.res_col AS answer
    ,Responses.res_created AS dateCreated
    ,Responses.res_notes AS note
    ,Responses.question_id AS questionID
    ,Responses.customer_id AS customerID
    ,Responses.res_answer AS subQuestion
    ,Responses.survey_id AS surveyID
    ,Responses.res_void AS void
    ,Customer.res_answer AS filter
FROM
    Responses, Responses AS Customer
WHERE
    rs.customer_id = Customer.customer_id
AND
    Responses.survey_id ='155' 
AND
    Customer.survey_id = '155'
AND
    Responses.question_id = '20'                    

AND CAST(Customer.res_answer AS VARCHAR(500)) = 'male'
AND Responses.res_void = '0' 

Answer 1

如果 2005 年不支持 Distinct，则按

分组

SELECT Distinct 
     Responses.res_id AS responseID
    ,Responses.res_col AS answer
    ,Responses.res_created AS dateCreated
    ,Responses.res_notes AS note
    ,Responses.question_id AS questionID
    ,Responses.customer_id AS customerID
    ,Responses.res_answer AS subQuestion
    ,Responses.survey_id AS surveyID
    ,Responses.res_void AS void
    ,'male'
FROM Responses
WHERE Responses.survey_id ='155' 
  AND Responses.question_id = '20'  
  AND Responses.res_void = '0'                  
  AND exists (select 1 from Responses c 
              where c.res_answer = 'male' 
                and c.survey_id  = '155'
                and c.ID = Responses.ID)