數據庫:
create table t1(id int primary key not null auto_increment,name varchar(32),password varchar(32)); insert into t1(name,password) values('admin','123'); insert into t1(name,password) values('zhangsan','123'); insert into t1(name,password) values('lisi','123');
Java代碼:
mysqlDao.java:
package com.dao; import java.sql.Connection; import java.sql.DriverManager; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import org.junit.Test; public class mysqlDao { private static String driver="com.mysql.jdbc.Driver"; //驅動 private String url="jdbc:mysql://localhost:3306/test"; //數據庫連接地址 private String user="root"; //數據庫賬戶 private String password="11"; //數據庫密碼 private Connection connection=null; //連接 private Statement stmt=null; //聲明 private ResultSet rs=null; //結果集 private int i=-1; /* * 創建驅動 * */ static{ try { Class.forName(driver); } catch (ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } } /* * 加載驅動 * */ @Test public void connect() { // TODO Auto-generated method stub try { connection=DriverManager.getConnection(url, user, password); if(connection!=null){ System.out.println("數據庫連接成功!"); }else{ System.out.println("數據庫連接失敗!"); } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } /* * 執行sql語句 * */ public void doSql(String sql) { // TODO Auto-generated method stub System.out.println("This Is mysqlDao.doSql() Method!"); if(sql!=null){ connect(); try { stmt=connection.createStatement(); stmt.execute(sql); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } /* * 獲取影響行數 * */ public int getUpCount() { // TODO Auto-generated method stub try { i=stmt.getUpdateCount(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return i; } /* * 獲取結果集 * */ public ResultSet getRs() { try { rs=stmt.getResultSet(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } return rs; } /* * 執行關閉方法 * */ public void close() { // TODO Auto-generated method stub try { if(rs!=null){ rs.close(); } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); }finally{ try { if(stmt!=null){ stmt.close(); } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); }finally{ if(connection!=null){ try { connection.close(); } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } } } }
package com.dao; import java.sql.ResultSet; import java.sql.SQLException; import org.junit.Test; public class createSql { mysqlDao mysqldao=new mysqlDao(); private String sql; private int i=-1; private ResultSet rs=null; /* * 插入數據 * */ @Test public void insert() { // TODO Auto-generated method stub sql="insert into t1(name,password) values('lisi','1234')"; //創建sql語句 mysqldao.doSql(sql); //執行sql語句 i=mysqldao.getUpCount(); //獲取影響行數 if(i!=-1){ System.out.println("數據插入成功!"); }else{ System.out.println("數據插入失敗!"); } mysqldao.close(); //關閉連接 } /* * 刪除數據 * */ @Test public void delete() { // TODO Auto-generated method stub sql="delete from t1 where id=6"; mysqldao.doSql(sql); i=mysqldao.getUpCount(); if(i!=-1){ System.out.println("數據刪除成功!"); }else{ System.out.println("數據刪除失敗!"); } mysqldao.close(); } /* * 修改數據 * */ @Test public void update() { // TODO Auto-generated method stub sql="update t1 set name='wangwu' where id=1"; mysqldao.doSql(sql); i=mysqldao.getUpCount(); if(i!=-1){ System.out.println("數據更新成功!"); }else{ System.out.println("數據更新失敗!"); } mysqldao.close(); } /* * 遍歷數據 * */ @Test public void select() throws SQLException { // TODO Auto-generated method stub sql="select * from t1"; mysqldao.doSql(sql); rs=mysqldao.getRs(); if(rs!=null){ rs.last(); i=rs.getRow(); if(i>0){ rs.beforeFirst(); while(rs.next()){ String id=rs.getString("id"); String name=rs.getString("name"); String password=rs.getString("password"); System.out.println("id:"+id+" "+"name:"+name+" password:"+password); } }else{ System.out.println("對不起,沒有您要查詢的信息!"); } }else{ System.out.println("異常..........."); } mysqldao.close(); } }