掌握Java开发数据库连接技术:从基础到高级应用

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// 典型约会...啊不,数据库操作流程 Connection conn = null; try {

conn = DriverManager.getConnection(url, username, password);
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery("SELECT * FROM users");
while(rs.next()) {
    System.out.println(rs.getString("username"));
}

} finally {

if(conn != null) conn.close(); // 记得说再见!

}

// Hibernate施展的保存魔法 Session session = sessionFactory.openSession(); Transaction tx = session.beginTransaction(); User user = new User("魔法师", "magic@hibernate.com"); session.save(user); // 挥动魔杖! tx.commit(); session.close();

// 使用连接池就像叫专车 DataSource dataSource = new HikariDataSource(config); try (Connection conn = dataSource.getConnection()) {

// 你的数据库操作

} // 自动"还车",不用手动close

@Entity @Table(name="library_books") public class Book {

@Id
@GeneratedValue(strategy=GenerationType.IDENTITY)
private Long id;  // 主键自增

@Column(length=100, nullable=false)
private String title;

@Temporal(TemporalType.DATE)
private Date publishDate;  // 精确到年月日

}

// 查询所有价格高于指定值的书籍 public List findExpensiveBooks(double minPrice) {

String sql = "SELECT * FROM books WHERE price > ?";
return jdbcTemplate.query(sql, new Object[]{minPrice}, 
    (rs, rowNum) -> new Book(
        rs.getLong("id"),
        rs.getString("title"),
        rs.getDouble("price")
    ));

}

标签: #Java数据库连接 #JDBC操作指南 #Hibernate ORM技术 #数据库连接池优化 #Java开发高效数据库操作