smallkun/class-notes
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smallkun 2025-02-27 17:28:52 +08:00
parent 9219d6cc3c
commit 53aacb1dee
1 changed files with 8 additions and 2 deletions
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10
2208/天天乐学考试答案/MySQL练习（一）.md
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@ -230,13 +230,19 @@ FROM tb_books b;
UPDATE tb_books b UPDATE tb_books b
SET b.note = SUBSTR(b.note,INSTR(b.note,'-')+2); SET b.note = SUBSTR(b.note,INSTR(b.note,'-')+2);
#7 tj11 #7 tj11 多表连接+条件+排序
SELECT b.book_id, b.title, a.author_id, a.author_name, b.publication_date SELECT b.book_id, b.title, a.author_id, a.author_name, b.publication_date
FROM tb_books b, tb_authors a FROM tb_books b, tb_authors a
WHERE b.note = a.author_name AND YEAR(b.publication_date) BETWEEN 1980 AND 2010 WHERE b.note = a.author_name AND YEAR(b.publication_date) BETWEEN 1980 AND 2010
ORDER BY b.publication_date DESC; ORDER BY b.publication_date DESC;
#8 #8 tj12 多表连接+分组+分组后条件
SELECT a.author_id, a.author_name, COUNT(*)
FROM tb_books b, tb_authors a
WHERE b.note = a.author_name
GROUP BY a.author_id
HAVING COUNT(*) > 1;
#9 #9
``` ```