java操作mysql的增删改查

prepareStatement(sql)是statement的子类，比statement好用。

如果数据库中定义的是int值，那么sql语句中要把int单独提出来。如".....values("+8329+","+34243+",'mm','789')"

下载java 数据库驱动jdbc，请戳这里http://pan.baidu.com/s/1sjPgT8T

package com.cn.edu;

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

public class helloworld {
private Connection conn = null;
PreparedStatement statement = null;

// connect to MySQL
void connSQL() {
String url = "jdbc:mysql://localhost:3306/hello?characterEncoding=UTF-8";
String username = "root";
String password = "root"; // 加载驱动程序以连接数据库
try {
Class.forName("com.mysql.jdbc.Driver" );
conn = DriverManager.getConnection( url,username, password );
}
//捕获加载驱动程序异常
catch ( ClassNotFoundException cnfex ) {
System.err.println(
"装载 JDBC/ODBC 驱动程序失败。" );
cnfex.printStackTrace();
}
//捕获连接数据库异常
catch ( SQLException sqlex ) {
System.err.println( "无法连接数据库" );
sqlex.printStackTrace();
}
}

// disconnect to MySQL
void deconnSQL() {
try {
if (conn != null)
conn.close();
} catch (Exception e) {
System.out.println("关闭数据库问题 ：");
e.printStackTrace();
}
}

// execute selection language
ResultSet selectSQL(String sql) {
ResultSet rs = null;
try {
statement = conn.prepareStatement(sql);
rs = statement.executeQuery(sql);
} catch (SQLException e) {
e.printStackTrace();
}
return rs;
}

// execute insertion language
boolean insertSQL(String sql) {
try {
statement = conn.prepareStatement(sql);
statement.executeUpdate();
return true;
} catch (SQLException e) {
System.out.println("插入数据库时出错：");
e.printStackTrace();
} catch (Exception e) {
System.out.println("插入时出错：");
e.printStackTrace();
}
return false;
}
//execute delete language
boolean deleteSQL(String sql) {
try {
statement = conn.prepareStatement(sql);
statement.executeUpdate();
return true;
} catch (SQLException e) {
System.out.println("插入数据库时出错：");
e.printStackTrace();
} catch (Exception e) {
System.out.println("插入时出错：");
e.printStackTrace();
}
return false;
}
//execute update language
boolean updateSQL(String sql) {
try {
statement = conn.prepareStatement(sql);
statement.executeUpdate();
return true;
} catch (SQLException e) {
System.out.println("插入数据库时出错：");
e.printStackTrace();
} catch (Exception e) {
System.out.println("插入时出错：");
e.printStackTrace();
}
return false;
}
// show data in ju_users
void layoutStyle2(ResultSet rs) {
System.out.println("-----------------");
System.out.println("执行结果如下所示:");
System.out.println("-----------------");
System.out.println(" 用户ID" + "/t/t" + "淘宝ID" + "/t/t" + "用户名"+ "/t/t" + "密码");
System.out.println("-----------------");
try {
while (rs.next()) {
System.out.println(rs.getInt("ju_userID") + "/t/t"
+ rs.getString("taobaoID") + "/t/t"
+ rs.getString("ju_userName")
+ "/t/t"+ rs.getString("ju_userPWD"));
}
} catch (SQLException e) {
System.out.println("显示时数据库出错。");
e.printStackTrace();
} catch (Exception e) {
System.out.println("显示出错。");
e.printStackTrace();
}
}

public static void main(String args[]) {

helloworld h = new helloworld();
h.connSQL();
String s = "select * from ju_users";

String insert = "insert into ju_users(ju_userID,TaobaoID,ju_userName,ju_userPWD) values("+8329+","+34243+",'mm','789')";
String update = "update ju_users set ju_userPWD =123 where ju_userName= 'mm'";
String delete = "delete from ju_users where ju_userName= 'mm'";

if (h.insertSQL(insert) == true) {
System.out.println("insert successfully");
ResultSet resultSet = h.selectSQL(s);
h.layoutStyle2(resultSet);
}
if (h.updateSQL(update) == true) {
System.out.println("update successfully");
ResultSet resultSet = h.selectSQL(s);
h.layoutStyle2(resultSet);
}
if (h.insertSQL(delete) == true) {
System.out.println("delete successfully");
ResultSet resultSet = h.selectSQL(s);
h.layoutStyle2(resultSet);
}

h.deconnSQL();
}
}