1.链接数据库的基本步骤import java.sql.*; import java.util.Date; public class DBConnect { public static void main(String[] args) throws Exception { String url jdbc:mysql://localhost:3306/MyDB; String username root; String password 123456; ResultSet rs null; Statement st null; Connection conn null; try { //1. 加载驱动程序 Class.forName(com.mysql.cj.jdbc.Driver); //2. 获取数据库连接 conn DriverManager.getConnection(url, username, password); //3. 创建用于向数据库发送SQL命令的statement对象 st conn.createStatement(); //4. 执行SQL命令并获得结果集 ResultSet String sql select id,name,password,email,birthday from user; rs st.executeQuery(sql); //5. 对结果集中的数据进行操作 while (rs.next()) { int id (Integer) rs.getObject(id); String name (String) rs.getObject(name); String pd (String) rs.getObject(password); String email (String) rs.getObject(email); Date birthday (Date) rs.getObject(birthday); System.out.println(id , name , pd , email , birthday); } } // 关闭连接 finally { if (rs ! null) { try { rs.close(); } catch (Exception e) { e.printStackTrace(); } rs null; } if (st ! null) { try { st.close(); } catch (Exception e) { e.printStackTrace(); } st null; } if (conn ! null) { try { conn.close(); } catch (Exception e) { e.printStackTrace(); } conn null; } } } }测试结果2.Statement的三种SQL执行语句import java.io.InputStream; import java.sql.*; import java.util.Properties; public class JDBCUtils { private static String driver com.mysql.cj.jdbc.Driver; private static String url jdbc:mysql://localhost:3306/MyDB; private static String username root; private static String password 123456; public static Connection getConnection() throws SQLException { return DriverManager.getConnection(url, username, password); // 获得 connection } public static void release(Connection conn, Statement st, ResultSet rs) { // 释放资源 if (rs ! null) { try { rs.close(); } catch (Exception e) { e.printStackTrace(); } rs null; } if (st ! null) { try { st.close(); } catch (Exception e) { e.printStackTrace(); } st null; } if (conn ! null) { try { conn.close(); } catch (Exception e) { e.printStackTrace(); } conn null; } } }测试代码import java.sql.*; public class JDBCUtilsTest { static ResultSet rs null; static Statement st null; static Connection conn null; public static void main(String[] args) { try { conn JDBCUtils.getConnection(); st conn.createStatement(); String sql insert into user(id,name,password,email,birthday) values(4,邹叙畅, 123456,xuchangzh163.com,2003-06-14); // int num st.executeUpdate(sql); if (num0){ System.out.println(num); System.out.println(插入成功); } } catch (Exception e) { e.printStackTrace(); }finally { JDBCUtils.release(conn,st,rs); } } }测试结果3.对数据库进行增删改查import java.sql.*; import java.util.Date; public class DataManipulate { private Connection conn null; private Statement st null; private ResultSet rs null; public void insert() { try { conn JDBCUtils.getConnection(); st conn.createStatement(); String sql insert into user(id,name,password,email,birthday) values(4,邹叙畅, 123456,xuchangzh163.com,2003-06-14); // 返回的是该 sql 语句会影响数据库的行数 int num st.executeUpdate(sql); if (num 0) { System.out.println(num); System.out.println(插入成功); } } catch (Exception e) { e.printStackTrace(); } finally { JDBCUtils.release(conn, st, rs); } } public void delete() { try { conn JDBCUtils.getConnection(); st conn.createStatement(); String sql delete from user where password123; int num st.executeUpdate(sql); if (num 0) { System.out.println(num); System.out.println(删除成功); } } catch (Exception e) { e.printStackTrace(); } finally { JDBCUtils.release(conn, st, rs); } } public void update() { try { conn JDBCUtils.getConnection(); st conn.createStatement(); String sql update user set passwordabcd where name李东; // 此段代码对应图1左上角部分 int num st.executeUpdate(sql); if (num 0) { System.out.println(num); System.out.println(修改成功); } } catch (Exception e) { e.printStackTrace(); } finally { JDBCUtils.release(conn, st, rs); } } public void search() { try { conn JDBCUtils.getConnection(); st conn.createStatement(); String sql select id, name, password, email, birthday from user; rs st.executeQuery(sql); while (rs.next()) { int id (Integer) rs.getObject(id); String name (String) rs.getObject(name); String password (String) rs.getObject(password); String email (String) rs.getObject(email); Date birthday (Date) rs.getObject(birthday); System.out.println(id , name , password , email , birthday); } } catch (Exception e) { e.printStackTrace(); } finally { JDBCUtils.release(conn, st, rs); } } }测试代码public class DataManipulateTest { public static void main(String[] args) { DataManipulate dataManipulate new DataManipulate(); dataManipulate.insert(); dataManipulate.delete(); dataManipulate.search(); dataManipulate.update(); } }测试结果