本文实例讲述了JDBC操作数据库的增加、删除、更新、查找方法。分享给大家供大家参考，具体如下：
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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.建立连接 conn=JdbcUtils.getConnection(); //单例设计模式 conn=JdbcUtilsSingle.getInstance().getConnection(); //3.创建语句 st=conn.createStatement(); //4.执行语句 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.建立连接 conn=JdbcUtils.getConnection(); //单例设计模式 conn=JdbcUtilsSingle.getInstance().getConnection(); //3.创建语句 st=conn.createStatement(); //4.执行语句 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.建立连接 conn=JdbcUtils.getConnection(); //单例设计模式 conn=JdbcUtilsSingle.getInstance().getConnection(); //3.创建语句 st=conn.createStatement(); //4.执行语句 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.建立连接 conn=JdbcUtils.getConnection(); //单例设计模式 conn=JdbcUtilsSingle.getInstance().getConnection(); //3.创建语句 st=conn.createStatement(); //4.执行语句 resultset=st.executeQuery("select id,name,birthday,money from user"); //5.处理结果 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.释放资源 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(); } } } }} |
希望本文所述对大家Java程序设计有所帮助。
