1.邏輯刪除簡介

邏輯刪除是通過數(shù)據(jù)庫字段標(biāo)識來實現(xiàn)數(shù)據(jù)刪除操作

2.邏輯刪除實現(xiàn)

2.1. 在yml配置文件中添加配置

# mybatis-plus配置文件
mybatis-plus:
  # 指定mapper.xml文件位置
  mapper-locations: classpath*:mapper/*.xml
  # 邏輯刪除配置
  global-config:
    db-config:
      logic-not-delete-value: 0 #邏輯沒刪除
      logic-delete-value: 1 #邏輯已刪除

2.2. 在User中添加刪除標(biāo)識注解

   @TableLogic//刪除標(biāo)識
    private Integer deleted;//邏輯刪除標(biāo)識(0.未刪除,1.已刪除)

3.查詢中排除刪除標(biāo)識字段及注意事項

排除刪除標(biāo)識字段在查詢中顯示，自定義的不起作用

    @TableLogic//刪除標(biāo)識
    @TableField(select = false)//排除查詢顯示
    private Integer deleted;//邏輯刪除標(biāo)識(0.未刪除,1.已刪除)

package com.mp.delete;

import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.baomidou.mybatisplus.core.toolkit.Wrappers;
import com.mp.dao.UserMapper;
import com.mp.entity.User;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

import java.util.List;

/**
 * @Description //TODO
 * @Author LL
 * @Date 2020-03-26 16:47
 */
@SpringBootTest
@RunWith(SpringRunner.class)
public class deleteTest {

    private final static org.slf4j.Logger logger = LoggerFactory.getLogger(deleteTest.class);

    @Autowired
    private UserMapper userMapper;

    /**
     * 測試刪除前后
     */
    @Test
    public void deleteById(){
        List<User> usersB = userMapper.selectList(null);
        logger.warn("-->刪除前數(shù)據(jù)總數(shù)："+usersB.size());

        int rows = userMapper.deleteById(1172422496554401794L);
        logger.warn("-->刪除影響行數(shù)："+rows);

        List<User> usersA = userMapper.selectList(null);
        logger.warn("-->刪除后數(shù)據(jù)總數(shù)："+usersA.size());
        usersA.forEach(System.out::println);
    }

    /**
     * 測試刪除標(biāo)識是否器作用
     */
    @Test
    public void select(){
        LambdaQueryWrapper<User> lambdaQuery = Wrappers.lambdaQuery();
        lambdaQuery.gt(User::getAge, 20);
        List<User> users = userMapper.selectList(lambdaQuery);
//        List<Map<String, Object>> users = userMapper.selectMaps(lambdaQuery);
        users.forEach(System.out::println);
    }
}

自定義刪除方法驻子，得在條件中添加刪除過濾條件，或在SQL中添加刪除過濾條件

package com.mp.dao;

import com.baomidou.mybatisplus.core.conditions.Wrapper;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.baomidou.mybatisplus.core.toolkit.Constants;
import com.mp.entity.User;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Select;
import java.util.List;

/**
 * @Description 數(shù)據(jù)訪問層
 * @Author LL
 * @Date 2020-03-26 16:09
 */
public interface UserMapper extends BaseMapper<User> {

    @Select("select * from tb_user ${ew.customSqlSegment}")
    List<User> mySelectList(@Param(Constants.WRAPPER)Wrapper<User> wrapper);
}

  /**
     * 自定義刪除方法
     */
    @Test
    public void mySelect(){
        LambdaQueryWrapper<User> lambdaQuery = Wrappers.lambdaQuery();
        lambdaQuery.gt(User::getAge, 20).eq(User::getDeleted, 0);
        List<User> users = userMapper.mySelectList(lambdaQuery);
        users.forEach(System.out::println);
    }