测试
package com.itheima.dao;

import com.itheima.pojo.LinkMan;
import com.itheima.pojo.PageBean;
import com.itheima.utils.DruidUtil;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import org.apache.commons.dbutils.handlers.ScalarHandler;

import java.sql.SQLException;
import java.util.List;

/**
 * @author qiuji
 * @version 1.0
 * @date 2021-07-26 16:50
 */
public class LinkManDao {
    private QueryRunner queryRunner = new QueryRunner(DruidUtil.getDataSource());

    public void delete(String id) throws SQLException {
        String sql = "delete from linkman where id = ?";
        queryRunner.update(sql, id);
    }

    /**
     * 查询所有联系人
     *
     * @return
     * @throws SQLException
     */
    public List<LinkMan> findAll() throws SQLException {
        String sql = "select * from linkman";
        List<LinkMan> query = queryRunner.query(sql, new BeanListHandler<>(LinkMan.class));
        return query;
    }

    /**
     * 添加联系人
     *
     * @param linkMan
     * @throws SQLException
     */
    public void add(LinkMan linkMan) throws SQLException {
        String sql = "insert into linkman values(null,?,?,?,?,?,?)";
        queryRunner.update(sql,
                linkMan.getName(),
                linkMan.getSex(),
                linkMan.getAge(),
                linkMan.getAddress(),
                linkMan.getQq(),
                linkMan.getEmail()
        );
    }

    /**
     * 查找一条记录
     *
     * @param id
     * @return
     * @throws SQLException
     */
    public List<LinkMan> findOne(Integer id) throws SQLException {
        String sql = "select * from linkman where id = ?";
        List<LinkMan> list = queryRunner.query(sql, new BeanListHandler<>(LinkMan.class), id);
        return list;
    }

    public void update(LinkMan linkMan1) throws SQLException {
        //update里面占位符?不能加单引号 否则会识别不到 ?就成了单引号了
        String sql1 = "update linkman set name=?,sex=?,age=?,address=?,qq=?,email=? where id = ?";
        System.out.println( "update linkman set name='"+linkMan1.getName()
                +"',sex='"+linkMan1.getSex()+"',age="+linkMan1.getAge()
                +",address='"+linkMan1.getAddress()+"',qq='"+linkMan1.getQq()
                +"',email='"+linkMan1.getEmail()+"' where id = "+linkMan1.getId());
        queryRunner.update(sql1,
                linkMan1.getName(),
                linkMan1.getSex(),
                linkMan1.getAge(),
                linkMan1.getAddress(),
                linkMan1.getQq(),
                linkMan1.getEmail(),
                linkMan1.getId()
        );
    }
    /**
     * 查询总数据条数
     * @return
     */
    public Long findTotalSize() throws SQLException {
        String sql = "select count(*) from linkman";
        Long totalSize = (Long) queryRunner.query(sql, new ScalarHandler());
        return totalSize;
    }

    /**
     * 查询获取到的当前页数据
     * @param l
     * @param pageSize
     * @return
     * @throws SQLException
     */
    public List<LinkMan> findCurrentPageList(long l, Integer pageSize) throws SQLException {
        String sql = "select * from linkman limit ?,?";
        List<LinkMan> query = queryRunner.query(sql, new BeanListHandler<>(LinkMan.class), (l-1)*pageSize, pageSize);
        System.out.println(query);
        return query;
    }
}