package cn.ccnu; 
 
import java.sql.Connection; 
import java.sql.DriverManager; 
import java.sql.ResultSet; 
 
import com.mysql.jdbc.Statement; 
 
public class Demo1 { 
 
  public static void main(String[] args) throws Exception { 
    test(); 
  } 
 
  public static void test() throws Exception { 
    //1,注冊(cè)驅(qū)動(dòng) 
//   DriverManager.registerDriver(new com.mysql.jdbc.Driver()); 
//   System.getProperty("jdbc.driver", "con.mysql.jdbc.Driver"); 
    Class.forName("com.mysql.jdbc.Driver");//這三種注冊(cè)方式，推薦使用這種 
 
    //2，建立連接 
    //url格式 
    //JDBC:子協(xié)議:子名稱//主機(jī)名:端口/數(shù)據(jù)庫(kù)名稱 
    String url = "jdbc:mysql://localhost:3306/test";//如果是本機(jī)，也可以將localhost:3306省掉 
    String user = "root"; 
    String password = "123456"; 
    Connection conn = (Connection)DriverManager.getConnection(url, user, password); 
 
    //3，創(chuàng)建slq執(zhí)行語(yǔ)句 
    Statement st = (Statement) conn.createStatement(); 
 
    //4,執(zhí)行語(yǔ)句 
    ResultSet rs = st.executeQuery("select * from a"); 
     
    //5，處理執(zhí)行結(jié)果 
    while (rs.next()) { 
      System.out.println(rs.getObject(1)); 
    } 
 
    //6，關(guān)閉連接，釋放資源 
    rs.close(); 
    st.close(); 
    conn.close(); 
  } 
 
} 

package com.wfu.ch09;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class Test1 {
 public static void main(String[] args) {
 try {
  Class.forName("com.mysql.jdbc.Driver");//里面的名字一定不要寫(xiě)錯(cuò)，這個(gè)也是導(dǎo)入的
  //forName(String className) 返回與帶有給定字符串名的類(lèi)或接口相關(guān)聯(lián)的 Class 對(duì)象。
  Connection conn=DriverManager.getConnection("jdbc:mysql://localhost:3306/k-user","root","123456");//試圖建立到給定數(shù)據(jù)庫(kù) URL 的連接。
  Statement stmt=conn.createStatement(); //創(chuàng)建一個(gè) Statement 對(duì)象來(lái)將 SQL 語(yǔ)句發(fā)送到數(shù)據(jù)庫(kù)。

//  String insertsql="insert into k_user(userno,username,pwd) values('1002','張三','123')";
//  int x=stmt.executeUpdate(insertsql); //executeUpdate 返回一個(gè)int 型的數(shù)據(jù) 括號(hào)里面是一個(gè)字符串?dāng)?shù)據(jù)類(lèi)型，詳細(xì)內(nèi)容看文檔

  //(1) 對(duì)于 SQL 數(shù)據(jù)操作語(yǔ)言 (DML) 語(yǔ)句，返回行計(jì)數(shù)
  //(2) 對(duì)于不返回任何內(nèi)容的 SQL 語(yǔ)句，返回 0

//  if(x>0){
//  System.out.println("插入成功！");
//  }
//  String updateSql="update k_user set pwd='123456' where userno='1002'";
//  int x=stmt.executeUpdate(updateSql);
//  if(x>0){
//  System.out.println("更新成功！");
//  }
  String deleteSql="delete from k_user where userno='1002'";
  int x=stmt.executeUpdate(deleteSql);
  if(x>0){
  System.out.println("刪除成功！");
  }
  String sql="select * from k_user";
  ResultSet rs=stmt.executeQuery(sql);
  while(rs.next()){
  for(int i=1;i<=13;i++){
   System.out.print(rs.getString(i)+" ");
  }
  System.out.println();
  }
  rs.close();
  stmt.close();
  conn.close();
 } catch (ClassNotFoundException e) {
  // TODO Auto-generated catch block
  e.printStackTrace();
 } catch (SQLException e) {
  // TODO Auto-generated catch block
  e.printStackTrace();
 }  
 }
}

package com.wfu.ch09;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class Test2 {
 public static void main(String[] args) {
 try {
  // step1：加載JDBC驅(qū)動(dòng)程序
  Class.forName("com.mysql.jdbc.Driver");
  // step2:建立數(shù)據(jù)庫(kù)的連接
  Connection conn = DriverManager.getConnection(
   "jdbc:mysql://localhost:3306/stock11", "root", "123");
//  // step3:創(chuàng)建Statement對(duì)象
  Statement st = conn.createStatement();
  //step4:執(zhí)行SQL語(yǔ)句
  String selectSql="select * from k_user";
  //step5：處理結(jié)果集
  ResultSet rs=st.executeQuery(selectSql);
  while(rs.next()){
  for(int i=1;i<=13;i++){
   System.out.print(rs.getString(i)+" ");
  }
  System.out.println();
//  String x=rs.getString("hometown");
//  System.out.println(x);
  }
  //step6：關(guān)閉創(chuàng)建的對(duì)象
  //關(guān)閉結(jié)果集
  rs.close();
  //關(guān)閉statement對(duì)象
  st.close();
  //關(guān)閉連接
  conn.close();


  // step4： 執(zhí)行SQL語(yǔ)句
////  String insertSql = "insert into k_user(userno,username,pwd) values('1001','tom','123')";
//  int x = st.executeUpdate(insertSql);
//  if(x>0){
//  System.out.println("插入成功！");
//  }
//  String updateSql="update k_user set pwd='123456' where userno='1001'";
//  int x=st.executeUpdate(updateSql);
//  if(x>0){
//  System.out.println("更新成功！");
//  }
//  String deleteSql="delete from k_user where userno='1001'";
//  int x=st.executeUpdate(deleteSql);
//  if(x>0){
//  System.out.println("刪除成功！");
//  }
  //

 } catch (ClassNotFoundException e) {
  // TODO Auto-generated catch block
  e.printStackTrace();
 } catch (SQLException e) {
  // TODO Auto-generated catch block
  e.printStackTrace();
 }
 }

}

Class.forName("DriverName")

Class.forName("com.mysql.jdbc.Driver");

Connection conn = DriverManager.getConnection(String url,String user,String password);

jdbc : < subprotocol> : < subname>

jdbc:mysql://serverName:port/instance

Connection conn = DriverManager.getConnection(
  "jdbc:mysql://localhost:3306/haier", "root", "123");

Statement smt = conn.createStatement();

int row=stmt.executeUpdate(sql);