java操作mysql的增删改查

最新推荐文章于 2023-06-07 19:13:44 发布

转载最新推荐文章于 2023-06-07 19:13:44 发布 · 535 阅读

Java 专栏收录该内容

69 篇文章

订阅专栏

本文提供了一个使用Java连接MySQL数据库的示例代码，演示了如何建立连接、执行增删改查操作，并展示查询结果。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

其中，需要把mysql与java连接的jar（mysql-connector-java-5.1.6-bin.jar）包导入工程.

[java] view plain copy

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();
}
}