From 7325659e82fbabafce754201dd230642305cab60 Mon Sep 17 00:00:00 2001
From: p84qj6krp <18879038841@163.com>
Date: Fri, 27 Dec 2024 14:59:16 +0800
Subject: [PATCH] Delete 'DataBase_operate.sql'

---
 DataBase_operate.sql | 211 -------------------------------------------
 1 file changed, 211 deletions(-)
 delete mode 100644 DataBase_operate.sql

diff --git a/DataBase_operate.sql b/DataBase_operate.sql
deleted file mode 100644
index d8843c8..0000000
--- a/DataBase_operate.sql
+++ /dev/null
@@ -1,211 +0,0 @@
--- (1) 比较条件查询： 需求： 查询所有借阅日期早于2024年1月1日的借阅记录，返回借阅ID、读者ID、图书ID和借阅日期。 
-　　SELECT loan_id, reader_id, book_id, loan_dateFROM LoanRecordWHERE loan_date < '2024-01-01';
--- (2) 需求： 查询借阅超过30天的图书借阅记录，返回借阅ID、读者ID、图书ID、借阅日期和应还日期。 
-　　SELECT loan_id, reader_id, book_id, loan_date, due_dateFROM LoanRecordWHERE DATEDIFF(CURRENT_DATE, loan_date) > 30;
--- (3) 需求：查询借书次数超过５次的读者姓名
-SELECT R.reader_name
-FROM Reader R
-JOIN Loan L ON R.reader_id = L.reader_id
-GROUP BY R.reader_name
-HAVING COUNT(L.loan_id) > 5;
--- (4)需求：查询借阅日期在２０２３年之后的所有图书标题
-SELECT B.book_title
-FROM Book B
-JOIN Loan L ON B.book_id = L.book_id
-WHERE L.loan_date > '2023-01-01';
--- (5) 集合比较查询： 需求： 查询所有节约过的图书ID和标题，且这些图书至少被两位不同的读者借阅过。 
-　　SELECT B.book_id, B.book_title
-　　FROM Book B
-　　JOIN Loan L ON B.book_id = L.book_id
-　　GROUP BY B.book_id
-HAVING COUNT(DISTINCT L.reader_id) > 1;
--- (6)需求：查询所有曾经借阅过数学类图书的学生姓名
-SELECT DISTINCT R.reader_name
-FROM Reader R
-JOIN Loan L ON R.reader_id = L.reader_id
-JOIN Book B ON L.book_id = B.book_id
-WHERE B.book_type = '数学' AND R.reader_type = '学生';
--- (7)范围比较查询：需求：查询借阅时长在３０天以上的所有借阅记录
-　　SELECT L.loan_id, R.reader_name, B.book_title, DATEDIFF(L.return_date, L.loan_date) AS loan_duration
-　　FROM Loan L
-　　JOIN Reader R ON L.reader_id = R.reader_id
-　　JOIN Book B ON L.book_id = B.book_id
-　　WHERE DATEDIFF(L.return_date, L.loan_date) > 30;
--- (8)需求：查询借阅期限为２０到６０天的图书
-SELECT L.loan_id, R.reader_name, B.book_title
-FROM Loan L
-JOIN Reader R ON L.reader_id = R.reader_id
-JOIN Book B ON L.book_id = B.book_id
-WHERE DATEDIFF(L.return_date, L.loan_date) BETWEEN 20 AND 60;
--- (9)字符串相似比较：需求：查询标题中包含“数据”的所有图书信息
-SELECT B.book_id, B.book_title, B.author
-FROM Book B
-WHERE B.book_title LIKE '%数据%';
--- (10)需求：查询所有以“王”字为开头的读者姓名
-SELECT R.reader_name
-FROM Reader R
-WHERE R.reader_name LIKE '王%';
--- (11)多表连接查询： 需求：查询每位读者借阅的所有图书标题及借阅日期
-SELECT R.reader_name, B.book_title, L.loan_date
-FROM Loan L
-JOIN Reader R ON L.reader_id = R.reader_id
-JOIN Book B ON L.book_id = B.book_id;
--- (12)需求：查询每位教师的借阅规则，包括借阅数量、借阅期限。
-SELECT R.reader_name, RLR.max_books, RLR.loan_duration, RLR.max_renewals
-FROM Reader R
-JOIN ReaderLoanRules RLR ON R.reader_id = RLR.reader_id
-WHERE R.reader_type = '教师';
--- (12)嵌套查询：需求：查询借阅超过３本书的学生姓名。
-SELECT R.reader_name
-FROM Reader R
-WHERE R.reader_type = '学生'
-AND R.reader_id IN (
-    SELECT L.reader_id
-    FROM Loan L
-    GROUP BY L.reader_id
-    HAVING COUNT(L.loan_id) > 3
-);
--- (13)需求：查询借阅最多图书的读者姓名和借阅的图书数量
-SELECT R.reader_name, (SELECT COUNT(*) FROM Loan L WHERE L.reader_id = R.reader_id) AS book_count
-FROM Reader R
-ORDER BY book_count DESC
-LIMIT 1;
--- (14)EXISTS查询：需求：查询至少借阅一本书的学生姓名
-SELECT R.reader_name
-FROM Reader R
-WHERE R.reader_type = '学生'
-AND EXISTS (
-    SELECT 1
-    FROM Loan L
-    WHERE L.reader_id = R.reader_id
-);
--- (15)需求：查询所有借阅过“计算机”类图书的教师姓名
-SELECT R.reader_name
-FROM Reader R
-WHERE R.reader_type = '教师'
-AND EXISTS (
-    SELECT 1
-    FROM Loan L
-    JOIN Book B ON L.book_id = B.book_id
-    WHERE L.reader_id = R.reader_id AND B.book_type = '计算机'
-);
--- (16)排序和分组：需求：查询借阅每个图书类别的借阅次数最多的图书
-SELECT B.book_title, B.book_type, COUNT(L.loan_id) AS loan_count
-FROM Loan L
-JOIN Book B ON L.book_id = B.book_id
-GROUP BY B.book_type, B.book_title
-ORDER BY loan_count DESC
-LIMIT 1;
--- (17)需求：查询每月借阅次数最多的读者姓名
-SELECT R.reader_name, COUNT(L.loan_id) AS loan_count
-FROM Loan L
-JOIN Reader R ON L.reader_id = R.reader_id
-WHERE YEAR(L.loan_date) = 2023
-GROUP BY MONTH(L.loan_date), R.reader_name
-ORDER BY loan_count DESC;
--- (18)需求：查询某本书是否被预约
-SELECT EXISTS (
-    SELECT 1
-    FROM ReservationRecord
-    WHERE book_id = 1
-) AS is_reserved;
--- (19)需求：查询未被预约的图书信息
-SELECT book_id, book_name, author FROM Book WHERE book_id NOT IN (SELECT book_id FROM ReservationRecord);
--- (20)需求：查询借阅记录中，归还日期晚于应还日期的记录
-SELECT loan_id, reader_id, book_id, loan_date, return_date FROM LoanRecord WHERE return_date > due_date;
--- 数据更新 --
--- 更新需求 1: 更新借阅记录的归还日期
-　　UPDATE LoanRecord
-　　SET return_date = '2024-12-20'
-WHERE reader_id = 1 AND return_date IS NULL;
-
--- 更新需求 2:更新图书的借阅状态为已借出
-　　UPDATE Book
-　　SET status = '已借出'
-WHERE book_id = 101;
-
--- 更新需求 3: 更新读者的联系方式 
-　　UPDATE Reader
-　　SET contact_info = '123-456-7890'
-　　WHERE reader_id = 5;
-
--- 更新需求 4: 更新罚款金额上限
-　　UPDATE FineRecord
-　　SET fine_amount = 100
-　　WHERE fine_amount > 100;
-
--- 更新需求 5: 更新图书分类为“编程语言” 
-　　UPDATE Book
-　　SET category_id = (SELECT category_id FROM BookCategory WHERE category_name = '编程语言')
-　　WHERE category_id = (SELECT category_id FROM BookCategory WHERE category_name = '计算机科学');
-
--- 更新需求 6: 更新借阅记录的应归还日期 
-　　UPDATE LoanRecord
-　　SET due_date = DATE_ADD(due_date, INTERVAL 10 DAY)
-　　WHERE loan_id = 123;
- 
--- 更新需求 7: 更新图书的出版日期 
-　　UPDATE Book
-　　SET publish_date = '2024-01-01'
-　　WHERE book_id = 201;
- 
--- 更新需求 8: 更改借阅记录的图书名称（若图书名称发生更改） 
-　　UPDATE LoanRecord L
-　　JOIN Book B ON L.book_id = B.book_id
-　　SET B.book_name = '高级编程'
-　　WHERE B.book_id = 50;
- 
--- 更新需求 9: 更新图书评论中的评分 
-　　UPDATE BookReview
-　　SET rating = 4
-　　WHERE book_id = 200;
- 
--- 更新需求 10: 更新读者借阅约状态为“冻结” 
-　　UPDATE Reader
-　　SET status = '冻结'
-　　WHERE reader_id = 3;
-
--- 数据删除 --
--- 删除需求 1: 删除过期预约记录 
-　　DELETE FROM ReservationRecord
-　　WHERE reservation_date < '2024-01-01';
- 
--- 删除需求 2: 删除图书类别为“小说”的所有图书 
-　　DELETE FROM Book
-　　WHERE category_id = (SELECT category_id FROM BookCategory WHERE category_name = '小说');
- 
--- 删除需求 3: 删除某个读者的所有借阅记录 
-　　DELETE FROM LoanRecord
-　　WHERE reader_id = 7;
- 
--- 删除需求 4: 删除已归还的借阅记录 
-　　DELETE FROM LoanRecord
-　　WHERE return_date IS NOT NULL;
- 
--- 删除需求 5: 删除没有罚款记录的读者
-　　DELETE FROM Reader
-　　WHERE reader_id NOT IN (SELECT DISTINCT reader_id FROM FineRecord);
- 
--- 删除需求 6: 删除借阅次数信号过２次的读者借阅记录
-　　DELETE FROM ReservationRecord
-　　WHERE reader_id IN (
-    SELECT reader_id
-    FROM LoanRecord
-    GROUP BY reader_id
-    HAVING COUNT(loan_id) > 2
-);
- 
--- 删除需求 7: 删除图书归还超过３０天的借阅记录 
-　　DELETE FROM LoanRecord
-　　WHERE DATEDIFF(CURRENT_DATE, return_date) > 30;
- 
--- 删除需求 8: 删除过期的罚款记录
-　　DELETE FROM FineRecord
-　　WHERE fine_date < '2023-12-31';
-
--- 删除需求 9: 删除所有失效的读者记录（失效是指没有借阅历史的读者） 
-　　DELETE FROM Reader
-　　WHERE reader_id NOT IN (SELECT DISTINCT reader_id FROM LoanRecord);
-
--- 删除需求 10: 删除无效的销售记录 
-　　DELETE FROM sales_records WHERE amount = 0;
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