Question

我有一个非常复杂的select语句，它使用内连接从表中返回计数统计信息（将其视为答案库 - 下面的复杂选择语句）。

这些答案与一个名为Questions_Bank_AnswerChoices（存储所有问题）的表相关。

我试图首先提出问题（来自Question_Bank_AnswerChoices表），然后将它们与统计数据（下面的复杂语句）进行匹配。下面的复杂陈述会提取统计数据，但除非已经回答，否则不会提出问题。

所以，如果没有人回答问题1，那么问题一不会出现在统计数据中，因为它没有包含在Answers表中（bc没有人回答）。

我怎样才能做到这一点？我认为我需要外联？

复杂选择声明：

WITH tbl as (
   SELECT 
      Questions_Bank.QuestionID, Questions_Bank.QuestionName,   
      REPLACE(Schools_Answers_Items.AnswerValue, '? ', ', ') as AnswerValue, 
      COUNT(Schools_Answers_Items.SchoolsAnswersItemID) AS CountAnswer,
      Schools_Answers_Items.SchoolID 
   FROM Questions_Bank 
   INNER JOIN Schools_Answers_Items
     ON Questions_Bank.QuestionID = Schools_Answers_Items.QuestionID 
   LEFT OUTER JOIN Schools_Answers  
     ON Schools_Answers_Items.SchoolsAnswerID = Schools_Answers.SchoolsAnswerID 
   WHERE (Questions_Bank.QuestionID = 1108) 
     AND (Schools_Answers.SchoolID = 103) 
   GROUP BY 
      Schools_Answers_Items.SchoolID,         
      Schools_Answers_Items.AnswerValue,
      Questions_Bank.QuestionID, 
      Questions_Bank.QuestionName
) 
SELECT 
   QuestionID, QuestionName, AnswerValue, CountAnswer, 
   SUM(CountAnswer) OVER () AS CountAllAnswers  
FROM tbl

Answer 1

尝试更改此

INNER JOIN Schools_Answers_Items
  ON Questions_Bank.QuestionID = Schools_Answers_Items.QuestionID

到

LEFT OUTER JOIN Schools_Answers_Items
  ON Questions_Bank.QuestionID = Schools_Answers_Items.QuestionID

您可能想删除此

AND (Schools_Answers.SchoolID = 103)

或用此

替换它

AND (Schools_Answers.SchoolID = 103 OR Schools_Answers.SchoolID IS NULL)

试试这个：

   SELECT 
      Questions_Bank.QuestionID, Questions_Bank.QuestionName,   
      REPLACE(Schools_Answers_Items.AnswerValue, '? ', ', ') as AnswerValue,
      Schools_Answers_Items.SchoolID 
   FROM Questions_Bank 
   LEFT OUTER JOIN Schools_Answers_Items
     ON Questions_Bank.QuestionID = Schools_Answers_Items.QuestionID 
   LEFT OUTER JOIN Schools_Answers  
     ON Schools_Answers_Items.SchoolsAnswerID = Schools_Answers.SchoolsAnswerID 
   WHERE Schools_Answers_Items.SchoolID

嵌套选择或内连接包括来自另一个表的行

1 个答案: