MySQL - 如何进行条件WHERE和OR子句查询？

Question

问题1：

我需要在WHERE子句中添加一个字段，并在我的存储过程中添加一个条件，那么在CASE条件下，以下查询的正确语法是什么？

问题2：

OR条件为我提供了以下条件0,1,2,3,4的所有记录（如果找不到，我需要tqm.is_imp = 1 tqm.is_imp IN (0,2,3,4))。我该怎么办？请帮忙。

tqm.is_imp = 1 OR tqm.is_imp IN (0,2,3,4)

我的查询：

 SELECT tqm.id INTO selectedQuestionNumber
    FROM tc_question_master tqm
    INNER JOIN tc_question_mapping tqmap ON tqmap.tc_question_id = tqm.id
    WHERE tqmap.syllabus_chapter_details_id IN (SELECT cms_id from topic where chapter_id IN (SELECT id from MyChapters))
    AND tqm.marks = CurMark
CASE WHEN CurQuestionType > 0 THEN
    AND tqm.question_type = CurQuestionType
END
    AND (tqm.level_of_question = 'Easy' OR tqm.level_of_question
    IN ('Moderate','Difficult','Very difficult'))
    AND (tqm.is_imp = 1 OR tqm.is_imp IN (0,2,3,4))
    AND tqm.id NOT IN (SELECT q.question_id FROM QBDetails q)
    ORDER BY RAND() LIMIT 1;

Answer 1

上半部分只是一个重新格式化，但当你接近一个案例表达式的逻辑时，它会更低，大部分都是纯粹的猜测。

SELECT
      tqm.id INTO selectedQuestionNumber
FROM tc_question_master tqm
INNER JOIN tc_question_mapping tqmap ON tqmap.tc_question_id = tqm.id
WHERE tqmap.syllabus_chapter_details_id IN (
      SELECT
            cms_id
      FROM topic
      WHERE chapter_id IN (
            SELECT
                  id
            FROM MyChapters
      )
)
AND (
     tqm.level_of_question = 'Easy'
  OR tqm.level_of_question IN ('Moderate', 'Difficult', 'Very difficult')
    )
AND (
    tqm.is_imp = 1
 OR tqm.is_imp IN (0, 2, 3, 4)
    )
AND tqm.id NOT IN (
      SELECT
            q.question_id
      FROM QBDetails q
)

    ## now it is really vague 
    AND (
         tqm.marks = CurMark
      OR 
        (CurQuestionType > 0 AND tqm.question_type = CurQuestionType)
        )
    ## end of guesswork

ORDER BY
      RAND()
LIMIT 1;