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突然心血来潮，想找一个BaseDao工具类，找半天找不到，就自己写了一个，方便后续使用。

package com.zzw.wxmall.dao;

import java.sql.*;

/**
 * @author zzw
 * @description TODO
 * @date 2022-11-11 15:18
 */
public class BaseDao {

    private final String DRIVER="com.mysql.cj.jdbc.Driver"; // mysql
//    private final String DRIVER="com.microsoft.sqlserver.jdbc.SQLServerDriver"; // SqlServer
    private final String URL= "jdbc:mysql://localhost:3306/数据库名?useUnicode=true&characterEncoding=UTF-8&serverTimezone=Asia/Shanghai"; // mysql
//    private final String URL= "jdbc:sqlserver://localhost:1433;databaseName=数据库名"; // SqlServer
    private final String USERNAME = "root"; // 用户名
    private final String PWD = "root"; // 密码



    private Connection connection;
    private PreparedStatement ps;
    protected ResultSet rs;

    /**
     * 打开连接
     */
    public void getConnection(){
        try {
            Class.forName(DRIVER);
            // 2在网络中查找数据库，创建连接对象
            connection = DriverManager.getConnection(
                    URL, USERNAME,PWD);
        } catch (ClassNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        //return connection;
    }

    /**
     * 关闭连接
     */
    public void closeAll(){
        try {
            // 释放资源（后打开的先关闭，先打开的后关闭）
            if (rs != null)
                rs.close();
            if (ps != null)
                ps.close();
            if (connection != null)
                connection.close();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

    }

    /**
     * 查询
     * @param sql
     * @param params
     */
    public void executeQuery(String sql , Object... params){
        try {
            getConnection();
            ps = connection.prepareStatement(sql);
            if(params!= null){
                for (int i = 0; i < params.length; i++) {
                    ps.setObject(i+1, params[i]);
                }
            }
            rs = ps.executeQuery();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }


    /**
     * 增、删、改
     * @param sql
     * @param params
     * @return
     */
    public int executeUpdate(String sql , Object... params){
        int result = -1;
        try {
            getConnection();
            ps = connection.prepareStatement(sql);
            if(params!= null){
                for (int i = 0; i < params.length; i++) {
                    ps.setObject(i+1, params[i]);
                }
            }
            result= ps.executeUpdate();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally{
            this.closeAll();
        }
        return result;
    }
    
}