图书管理系统入门项目
登录功能实现
数据库：
创建用户表：
对应的实体类：
public class User {
private int id;
private String userName;
private String password;}
添加set，get方法，构造器new时按照要求添加
方法
public User login(Connection conn,User user ) throws Exception {
User resUser = null;
String sql = "select * from user where userName=? and password=?";
PreparedStatement pt = conn.prepareStatement(sql);
pt.setString(1, user.getUserName());
pt.setString(2, user.getPassword());
ResultSet res = pt.executeQuery();
if(res.next()) {
resUser = new User();
resUser.setId(res.getInt("id"));
resUser.setUserName(res.getString("userName"));
resUser.setPassword(res.getString("password"));
}
return resUser;
}
数据库连接
/**
* 数据库连接
* @return
* @throws Exception
*/
public Connection getConn () throws Exception {
Class.forName("com.mysql.jdbc.Driver");
Connection conn=DriverManager.getConnection(dbUrl, dbUserName, dbPassword);
return conn;}
//关闭数据库
public void closeConn(Connection conn)throws Exception{
if(conn!=null)
conn.close();
}
创建图书表
实体类。。（各种省略）
添加图书：
public int add(Connection conn, Book book) throws Exception {
String sql = "insert into book values (null,?,?,?,?,?)";
PreparedStatement pmt = conn.prepareStatement(sql);
pmt.setObject(1, book.getBookName());
pmt.setObject(2, book.getAutor());
pmt.setObject(3, book.getTotalStock());
pmt.setObject(4, book.getPresentStock());
pmt.setObject(5, book.getBookTypeUId());
return pmt.executeUpdate();//返回改变记录数
}
查询：
public ResultSet list(Connection conn,Book book) throws Exception {
StringBuffer sb = new StringBuffer("select * from book,book_type where book.bookTypeId = book_type.id ");
if(StringUtil.isNotEmpty(book.getBookName())) {
sb.append("and book.bookName like '%"+book.getBookName()+"%'");
}
if(StringUtil.isNotEmpty(book.getAutor())) {
sb.append("and book.autor like '%"+book.getAutor()+"%'");
}
if(book.getBookTypeUId()!=null&& book.getBookTypeUId()!=-1) {
sb.append("and book.bookTypeId = "+book.getBookTypeUId());
}
PreparedStatement pmt=conn.prepareStatement(sb.toString());
return pmt.executeQuery();//返回结果集
}
删除图书：
public int delete(Connection conn ,String id)throws Exception{
String sql = "delete from book where id = ?";
PreparedStatement pmt = conn.prepareStatement(sql);
pmt.setObject(1, id);
return pmt.executeUpdate();//返回删除数
}
修改图书信息：
public int update(Connection conn , Book book)throws Exception{
String sql = "update book set bookName = ?,autor = ?,bookTypeId = ? where id = ?";
PreparedStatement pmt = conn.prepareStatement(sql);
pmt.setObject(1, book.getBookName());
pmt.setObject(2, book.getAutor());
pmt.setObject(3, book.getBookTypeUId());
pmt.setObject(4, book.getId());
return pmt.executeUpdate(); //返回修改数
}
图书管理简单的几个功能实现。！！
