JDBC操作數據庫的增長、刪除、更新、查找實例剖析。本站提示廣大學習愛好者:(JDBC操作數據庫的增長、刪除、更新、查找實例剖析)文章只能為提供參考,不一定能成為您想要的結果。以下是JDBC操作數據庫的增長、刪除、更新、查找實例剖析正文
本文實例講述了JDBC操作數據庫的增長、刪除、更新、查找辦法。分享給年夜家供年夜家參考,詳細以下:
package cn.com.JDBC; import java.sql.Connection; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; public class CRUD { public static void main(String[] args) throws SQLException { // TODO Auto-generated method stub //create(); //update(); delete(); read(); } static void delete() throws SQLException { Connection conn=null; Statement st=null; ResultSet resultset=null; try { //2.樹立銜接 conn=JdbcUtils.getConnection(); //單例設計形式 conn=JdbcUtilsSingle.getInstance().getConnection(); //3.創立語句 st=conn.createStatement(); //4.履行語句 String sql="delete from user where id>5"; int i=st.executeUpdate(sql); System.out.println("i="+i); } finally { JdbcUtils.free(resultset, st, conn); } } static void update() throws SQLException { Connection conn=null; Statement st=null; ResultSet resultset=null; try { //2.樹立銜接 conn=JdbcUtils.getConnection(); //單例設計形式 conn=JdbcUtilsSingle.getInstance().getConnection(); //3.創立語句 st=conn.createStatement(); //4.履行語句 String sql="update user set money=money+20"; int i=st.executeUpdate(sql); System.out.println("i="+i); } finally { JdbcUtils.free(resultset, st, conn); } } static void create() throws SQLException { Connection conn=null; Statement st=null; ResultSet resultset=null; try { //2.樹立銜接 conn=JdbcUtils.getConnection(); //單例設計形式 conn=JdbcUtilsSingle.getInstance().getConnection(); //3.創立語句 st=conn.createStatement(); //4.履行語句 String sql="insert into user(name,birthday,money) values('wy','2011-09-23','2894656')"; int i=st.executeUpdate(sql); System.out.println("i="+i); } finally { JdbcUtils.free(resultset, st, conn); } } static void read() throws SQLException { Connection conn=null; Statement st=null; ResultSet resultset=null; try { //2.樹立銜接 conn=JdbcUtils.getConnection(); //單例設計形式 conn=JdbcUtilsSingle.getInstance().getConnection(); //3.創立語句 st=conn.createStatement(); //4.履行語句 resultset=st.executeQuery("select id,name,birthday,money from user"); //5.處置成果 while(resultset.next()) { System.out.println(resultset.getObject("id")); System.out.println(resultset.getObject("name")); System.out.println(resultset.getObject("birthday")); System.out.println(resultset.getObject("money")); } } finally { JdbcUtils.free(resultset, st, conn); } } } package cn.com.JDBC; import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; public class JdbcUtils { private static String url="jdbc:mysql://localhost:3306/jdbc"; private static String user="root"; private static String password="123"; private JdbcUtils() { } static { try { Class.forName("com.mysql.jdbc.Driver"); } catch(ClassNotFoundException e) { throw new ExceptionInInitializerError(e); } } public static Connection getConnection() throws SQLException { return DriverManager.getConnection(url, user, password); } public static void free(ResultSet resultset,Statement st,Connection conn) { //6.釋放資本 try{ if(resultset!=null) resultset.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } finally { try { if(st!=null) st.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } finally { if(conn!=null) try { conn.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } } }
願望本文所述對年夜家Java法式設計有所贊助。