定时查询数据库某一字段为空（MySQL）

用java+sql定时对MySQL进行查询，将“pace_name”为空的行提取出来

PicDao.java

package example.dao;

import example.bean.PicBean;
import example.util.DBUtil;
import org.apache.commons.lang3.StringUtils;

import java.sql.*;
import java.util.ArrayList;
import java.util.List;

public class PicDao {

    //通过路径获取图片信息
    public static PicBean GetThePicByPath(String path) {
        String sql = "select * from pic where pic_path = "+path;
        Connection conn = DBUtil.getConnection();
        Statement state = null;
        ResultSet rs = null;
        PicBean test = new PicBean();
        try {
            state = conn.createStatement();
            rs = state.executeQuery(sql);
            while (rs.next()) {
                int id  = rs.getInt("id");
                String username = rs.getString("username");
                String pic_path = rs.getString("pic_path");
                String pic_name = rs.getString("pic_name");
                String pic_type = rs.getString("pic_type");
                int pic_type_number = rs.getInt("pic_type_number");
                String pic_time = rs.getString("pic_time");
                String pic_position_sheng = rs.getString("pic_position_sheng");
                String pic_position_shi = rs.getString("pic_position_shi");
                String pic_position_xian = rs.getString("pic_position_xian");
                String facename = rs.getString("face_name");

                test.setId(id);
                test.setUsername(username);
                test.setPic_name(pic_name);
                test.setPic_path(pic_path);
                test.setPic_type(pic_type);
                test.setPic_type_number(pic_type_number);
                test.setPic_time(pic_time);
                test.setPic_position_sheng(pic_position_sheng);
                test.setPic_position_shi(pic_position_shi);
                test.setPic_position_xian(pic_position_xian);
                test.setFace_name(facename);

            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            DBUtil.close(rs, state, conn);
        }
        return test;
    }

    //取出所有facename为空的行
    public static List<PicBean> ListFaceNameNULL() {
        String sql = "select * from pic";
        List<PicBean> test = new ArrayList<>();
        Connection conn = DBUtil.getConnection();
        Statement state = null;
        ResultSet rs = null;
        try {
            state = conn.createStatement();
            rs = state.executeQuery(sql);
            while (rs.next()) {

                String pic_type = rs.getString("pic_type");
                String facename = rs.getString("face_name");
                //System.out.println(pic_type+" "+facename);

                if(pic_type.equals("人") && StringUtils.isBlank(facename)){

                    int id  = rs.getInt("id");
                    String username = rs.getString("username");
                    String pic_path = rs.getString("pic_path");
                    String pic_name = rs.getString("pic_name");
                    int pic_type_number = rs.getInt("pic_type_number");
                    String pic_time = rs.getString("pic_time");
                    String pic_position_sheng = rs.getString("pic_position_sheng");
                    String pic_position_shi = rs.getString("pic_position_shi");
                    String pic_position_xian = rs.getString("pic_position_xian");

                    PicBean test1 = new PicBean();
                    test1.setId(id);
                    test1.setUsername(username);
                    test1.setPic_name(pic_name);
                    test1.setPic_path(pic_path);
                    test1.setPic_type(pic_type);
                    test1.setPic_type_number(pic_type_number);
                    test1.setPic_time(pic_time);
                    test1.setPic_position_sheng(pic_position_sheng);
                    test1.setPic_position_shi(pic_position_shi);
                    test1.setPic_position_xian(pic_position_xian);
                    test1.setFace_name(facename);

                    System.out.println("facename为空的id："+id);
                    test.add(test1);

                }

            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            DBUtil.close(rs, state, conn);
        }
        //System.out.println(test);
        return test;
    }

    //给facename打标签
    public static boolean ChangeTheFaceName(int id, String facename) {
        Connection conn = DBUtil.getConnection();
        boolean flag = false;

        try {
            String sql = "update pic set face_name = '"+facename + "' where id = '"+id+"'";

            System.out.println(sql);
            PreparedStatement pstmt = conn.prepareStatement(sql);
            int i = pstmt.executeUpdate();
            pstmt.close();
            conn.close();
            if(i>0) {
                flag = true;
            }

        } catch (SQLException e) {
            e.printStackTrace();
        }

        return flag;
    }

}

index.java

package example.total;

import example.bean.PicBean;
import example.dao.FaceDao;
import example.dao.PicDao;

import java.util.List;

public class index {
    public static void main(String[] args) throws InterruptedException {

        for(int i = 0; i < 10; i++){

            List<PicBean> pic = PicDao.ListFaceNameNULL();

            //判断是否存在facename为空的行
            if (pic.isEmpty()){
                System.out.println("执行第"+ i+1 +"次！");
                Thread.sleep(5000);
            }else{

                System.out.println("执行第"+ i+1 +"次！");

                //System.out.println(pic.size());
                //逐个将facename插入到表中
                for(int j = 0; j < pic.size(); j++){

                    int id = pic.get(j).getId();
                    String path = pic.get(j).getPic_path();
                    System.out.println(id+":"+path);

                    String facename = FaceDao.searchface(path);
                    System.out.println(facename);

                    PicDao.ChangeTheFaceName(id,facename);
                }

            }
        }

    }
}