From 255f778b3b5685ada534c90f627063364d722e82 Mon Sep 17 00:00:00 2001
From: p84qj6krp <18879038841@163.com>
Date: Fri, 27 Dec 2024 14:46:31 +0800
Subject: [PATCH] ADD file via upload

---
 DataBase_operate.sql | 211 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 211 insertions(+)
 create mode 100644 DataBase_operate.sql

diff --git a/DataBase_operate.sql b/DataBase_operate.sql
new file mode 100644
index 0000000..d8843c8
--- /dev/null
+++ b/DataBase_operate.sql
@@ -0,0 +1,211 @@
+-- (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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