实现菜单
首先我们想确定我们的图书管理需要实现哪些功能？我们这里实现最基础的增删改查。
我们这里先实现数据库的链接，以及一个简单的菜单。
#include <iostream>
#include <string>
// MySQL Connector/C++ 核心头文件
#include <mysql_driver.h> // MySQL驱动接口
#include <mysql_connection.h> // 数据库连接类
#include <cppconn/statement.h> // SQL语句执行接口
#include <cppconn/resultset.h> // 结果集处理类
#include <cppconn/exception.h> // SQL异常类void addBook(sql::Connection *con);void deleteBook() {};void viewBook() {};void updateBook() {};int main() {try {// 创建链接sql::mysql::MySQL_Driver *driver = sql::mysql::get_mysql_driver_instance();sql::Connection *con = driver->connect("tcp://127.0.0.1:3306", "root", "123456");con->setSchema("testdb");int choice;do { // 显示菜单std::cout << "\n==== 图书管理系统 ====\n""1. 增加图书\n""2. 查看所有图书\n""3. 更新图书\n""4. 删除图书\n""5. 退出系统\n";std::cin >> choice;if (choice == 1) addBook(con);else if (choice == 2) viewBook();else if (choice == 3) updateBook();else if (choice == 4) deleteBook();else if (choice == 5) break;else std::cout << "错误选项\n";} while (true);std::cout << "系统已退出\n";} catch (sql::SQLException &e) {std::cout << "数据库链接失败\n";}return 0;
}void addBook(sql::Connection *con) {}
添加图书
首先我们要确定的一点是，要操作数据库，就必须要获得sql::Connection，因此我们把函数的形参修改为
void addBook(sql::Connection *con);
我们在观察我们的表
+---------+------------------------+---------------+----------------+
| book_id | title | author | published_date |
+---------+------------------------+---------------+----------------+
| 1 | The Catcher in the Rye | J.D. Salinger | 1951-07-16 |
| 2 | Harry Potter | J.K. Rowing | 1997-06-26 |
| 1234 | The Hobbit | J.R.R Tolkien | 1937-09-21 |
| 1235 | 1984 | Orwell | 1949-06-08 |
+---------+------------------------+---------------+----------------+
我们这里只需要书名、作者、出版日期就好了。
这里面，我们为了可以对sql语句进行复用，我们这里引入了sql::PreparedStatement类，这个类简单来说就是可以?来作为占位符，后续在通过setString(), setInt()等方法将常数绑定到语句，并最后通过execute()调用来执行sql语句
因此我们最终的函数可以写成如下形式
void addBook(sql::Connection *con) {try {std::string title, author, date;std::cout << "请输入书名：\n";std::cin.ignore();std::getline(std::cin, title);std::cout << "请输入作者：\n";std::getline(std::cin, author);std::cout << "请输入出版日期(YYYY-MM-DD)：\n";std::getline(std::cin, date);sql::PreparedStatement *pstmt = con->prepareStatement("INSERT INTO books (title,author,published_date) VALUES (?,?,?)");pstmt->setString(1, title);pstmt->setString(2, author);pstmt->setString(3, date);pstmt->execute();std::cout << "图书添加成功\n";delete pstmt;} catch (sql::SQLException &e) {std::cout << "图书添加失败\n";}
}
当然了这里不需要复用，如果真的需要复用可以用lambda等方式封装即可。
查看所有图书
与插入相比，删除操作我们的语句是相对固定的，因此直接使用就好了。和之前从测试代码很类似。
void viewBook(sql::Connection *con) {try {sql::Statement *stmt = con->createStatement();sql::ResultSet *res = stmt->executeQuery("SELECT * FROM books");std::cout << "\n====图书列表====\n";while(res->next()) {std::cout << "ID: " << res->getInt("book_id") << "\n";std::cout << "标题: " << res->getString("title") << "\n";std::cout << "作者: " << res->getString("author") << "\n";std::cout << "出版日期: " << res->getString("published_date") << "\n";std::cout << "----------------------------------\n";}delete stmt;delete res;} catch (sql::SQLException &e) {std::cout << "ca\n";}
}
删除图书
要删除图书，我们只要得到图书的id就好了。
void deleteBook(sql::Connection *con) {try {int book_id;std::cout << "输入要删除图书的ID\n";std::cin >> book_id;sql::PreparedStatement *pstmt = con->prepareStatement("DELETE FROM books WHERE book_id = ?");pstmt->setInt(1, book_id);pstmt->execute();std::cout << "图书删除成功\n";delete pstmt;} catch (sql::SQLException &e) {std::cout << "图书删除失败\n";}
}
修改图书
修改图书其实有点类似把删除和添加拼起来。
void updateBook(sql::Connection *con) {try {int book_id;std::cout << "输入要更新图书的ID\n";std::cin >> book_id;std::string title, author, date;std::cout << "请输入书名：\n";std::cin.ignore();std::getline(std::cin, title);std::cout << "请输入作者：\n";std::getline(std::cin, author);std::cout << "请输入出版日期(YYYY-MM-DD)：\n";std::getline(std::cin, date);sql::PreparedStatement *pstmt = con->prepareStatement("UPDATE books SET title = ?, author = ?, published_date = ? WHERE book_id = ?");pstmt->setString(1, title);pstmt->setString(2, author);pstmt->setString(3, date);pstmt->setInt(4, book_id);pstmt->execute();std::cout << "图书更新成功\n";delete pstmt;} catch (sql::SQLException &e) {std::cout << "图书更新失败\n";}
}
完整代码
#include <iostream>
#include <string>
// MySQL Connector/C++ 核心头文件
#include <mysql_driver.h> // MySQL驱动接口
#include <mysql_connection.h> // 数据库连接类
#include <cppconn/statement.h> // SQL语句执行接口
#include <cppconn/resultset.h> // 结果集处理类
#include <cppconn/exception.h> // SQL异常类
#include <cppconn/prepared_statement.h>void addBook(sql::Connection *con);void deleteBook(sql::Connection *con);void viewBook(sql::Connection *con);void updateBook(sql::Connection *con);int main() {try {// 创建链接sql::mysql::MySQL_Driver *driver = sql::mysql::get_mysql_driver_instance();sql::Connection *con = driver->connect("tcp://127.0.0.1:3306", "root", "123456");con->setSchema("testdb");int choice;do { // 显示菜单std::cout << "\n==== 图书管理系统 ====\n""1. 增加图书\n""2. 查看所有图书\n""3. 更新图书\n""4. 删除图书\n""5. 退出系统\n";std::cin >> choice;if (choice == 1) addBook(con);else if (choice == 2) viewBook(con);else if (choice == 3) updateBook(con);else if (choice == 4) deleteBook(con);else if (choice == 5) break;else std::cout << "错误选项\n";} while (true);std::cout << "系统已退出\n";} catch (sql::SQLException &e) {std::cout << "数据库链接失败\n";}return 0;
}void addBook(sql::Connection *con) {try {std::string title, author, date;std::cout << "请输入书名：\n";std::cin.ignore();std::getline(std::cin, title);std::cout << "请输入作者：\n";std::getline(std::cin, author);std::cout << "请输入出版日期(YYYY-MM-DD)：\n";std::getline(std::cin, date);sql::PreparedStatement *pstmt = con->prepareStatement("INSERT INTO books (title,author,published_date) VALUES (?,?,?)");pstmt->setString(1, title);pstmt->setString(2, author);pstmt->setString(3, date);pstmt->execute();std::cout << "图书添加成功\n";delete pstmt;} catch (sql::SQLException &e) {std::cout << "图书添加失败\n";}
}void viewBook(sql::Connection *con) {try {sql::Statement *stmt = con->createStatement();sql::ResultSet *res = stmt->executeQuery("SELECT * FROM books");std::cout << "\n====图书列表====\n";while (res->next()) {std::cout << "ID: " << res->getInt("book_id") << "\n";std::cout << "标题: " << res->getString("title") << "\n";std::cout << "作者: " << res->getString("author") << "\n";std::cout << "出版日期: " << res->getString("published_date") << "\n";std::cout << "----------------------------------\n";}delete stmt;delete res;} catch (sql::SQLException &e) {std::cout << "ca\n";}
}void deleteBook(sql::Connection *con) {try {int book_id;std::cout << "输入要删除图书的ID\n";std::cin >> book_id;sql::PreparedStatement *pstmt = con->prepareStatement("DELETE FROM books WHERE book_id = ?");pstmt->setInt(1, book_id);pstmt->execute();std::cout << "图书删除成功\n";delete pstmt;} catch (sql::SQLException &e) {std::cout << "图书删除失败\n";}
}void updateBook(sql::Connection *con) {try {int book_id;std::cout << "输入要更新图书的ID\n";std::cin >> book_id;std::string title, author, date;std::cout << "请输入书名：\n";std::cin.ignore();std::getline(std::cin, title);std::cout << "请输入作者：\n";std::getline(std::cin, author);std::cout << "请输入出版日期(YYYY-MM-DD)：\n";std::getline(std::cin, date);sql::PreparedStatement *pstmt = con->prepareStatement("UPDATE books SET title = ?, author = ?, published_date = ? WHERE book_id = ?");pstmt->setString(1, title);pstmt->setString(2, author);pstmt->setString(3, date);pstmt->setInt(4, book_id);pstmt->execute();std::cout << "图书更新成功\n";delete pstmt;} catch (sql::SQLException &e) {std::cout << "图书更新失败\n";}
}
