JDBC操作数据库的增加、删除、更新、查找实例分析

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：

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。