IDEA实现JDBC数据库的增删查改

package jdbc; import jdbc.bean.Users; import jdbc.DBUtil.DButil; import java.sql.*; import java.util.ArrayList; import java.util.List; public class TestConnection { public List<Users> FindAll(){ Statement statement=null, statementadd,statementdel,statementupdate=null; ResultSet resultset = null; Connection conn = null; List<Users> list = new ArrayList<>(); try { //1.加载驱动2.创建连接 conn = DButil.Getconnection(); //3.sql语句 String sql = "select * from users"; String addsql="insert into users(user_id,user_name) values('0121812530721','杨洋');"; String delsql="delete from users where user_id='0121812070763'"; String updatasql="update users set user_name='刘翔' where user_id='1234567890123'"; //4.得到statement对象 statement = conn.prepareStatement(sql); statementadd = conn.prepareStatement(addsql); statementdel=conn.prepareStatement(delsql); statementupdate=conn.prepareStatement(updatasql); //5.执行sql ((PreparedStatement) statementadd).executeUpdate(); ((PreparedStatement) statementdel).executeUpdate(); ((PreparedStatement) statementupdate).executeUpdate(); //执行过增加、删除、修改后，最后再查询 resultset = ((PreparedStatement) statement).executeQuery(); // 6.处理结果集 while (resultset.next()) { String id = resultset.getString(1); String name = resultset.getString(2); Users users = new Users(id, name); list.add(users); } } catch (Exception e) { e.printStackTrace(); } finally { DButil.Close(resultset, conn, statement); } return list; } public static void main(String args[]) { List<Users> list = new ArrayList<>(); TestConnection testConnection =new TestConnection(); list=testConnection.FindAll(); System.out.println(list.toString()); } }