我正在嘗試對來自 SQLite 資料庫的三個表的不同值執行內部連接。我嘗試了很多次都失敗了。請指導我。
下面是我試圖實作的偽代碼
sql = '''
SELECT DISTINCT lesson_id, question_id FROM lesson_practice_questions as lpq
INNER JOIN
SELECT DISTINCT topic_id, lesson_id FROM chapter_lessons as cl
WHERE cl.topic_id==2
ON cl.lesson_id = lpq.lesson_id
INNER JOIN
SELECT DISTINCT question_id, subject_id, question_type_id, knowledge_type_ids complexity_level FROM questions as q
ON q.question_id = lpq.question_id;'''
cur.execute(sql)
非常感謝@eshirvana 抽出時間提供幫助！
具有模糊錯誤解決方案的完美解決方案，供將來的計算器參考：
sql = '''SELECT
lpq.lesson_id, cl.lesson_id,
topic_id,
q.question_id, lpq.question_id,
subject_id,
question_type_id,
knowledge_type_ids,
complexity
FROM lesson_practice_questions as lpq
INNER JOIN chapter_lessons as cl on cl.topic_id = 2 and cl.lesson_id = lpq.lesson_id
INNER JOIN questions as q ON q.question_id = lpq.question_id;'''
uj5u.com熱心網友回復：
這是正確的 sql 語法，但是如果這不是正確的輸出，您需要提供示例資料和所需的輸出：
SELECT
lpq.lesson_id,
question_id,
topic_id,
lesson_id,
question_id,
subject_id,
question_type_id,
knowledge_type_ids,
complexity_level
FROM lesson_practice_questions as lpq
INNER JOIN chapter_lessons as cl on cl.topic_id = 2 and cl.lesson_id = lpq.lesson_id
INNER JOIN questions as q ON q.question_id = lpq.question_id;
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