JAVA对MySQL数据库的操作

一、导包：

使用JDBC连接MySQL数据库时，首先需要导入一个第三方的JAR包（点击下载），下载解压得到一个JAR包，并导入到JAVA项目中，如下图：

二、DBHelper类：

代码如下：

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;

public class DBHelper {
    public static final String url = "jdbc:mysql://localhost/test";
    public static final String name = "com.mysql.jdbc.Driver";
    public static final String user = "root";
    public static final String password = "123456";

    public Connection conn = null;
    public PreparedStatement pst = null;

    public DBHelper(String sql) {
        try {
            Class.forName(name);// 指定连接类型
            conn = DriverManager.getConnection(url, user, password);// 获取连接
            pst = conn.prepareStatement(sql);// 准备执行语句
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public void close() {
        try {
            this.conn.close();
            this.pst.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

三、查询数据：

代码如下：

import java.sql.ResultSet;
import java.sql.SQLException;

public class Test {
    private static String sql = null;
    private static DBHelper helper = null;
    private static ResultSet rs = null;

    public static void main(String[] args) {
        sql = "select empno,ename from emp";
        helper = new DBHelper(sql);

        try {
            rs = helper.pst.executeQuery();
            while (rs.next()) {
                String empno = rs.getString(1);
                String ename = rs.getString(2);
                System.out.println(empno + "	" + ename + "	");
            }
            rs.close();
            helper.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

结果如下：

四、更新数据：

代码如下：

import java.sql.SQLException;

public class TestUpdate {
    private static String sql = null;
    private static DBHelper helper = null;

    public static void main(String[] args) {
        sql = "delete from emp where empno=1111";
        helper = new DBHelper(sql);

        try {
            int i = helper.pst.executeUpdate();
            if (i != 0) {
                System.out.println("删除成功");
            } else {
                System.out.println("删除失败");
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}