update user set del_flag=1 where id = 1 and del_flag=0

select id,name,del_flag from user where del_flag=0

mybatis-plus:
  global-config:
    db-config:
      logic-delete-field: flag # 全局邏輯刪除的實體字段名(since 3.3.0,配置后可以忽略不配置步驟2)
      logic-delete-value: 1 # 邏輯已刪除值(默認為 1)
      logic-not-delete-value: 0 # 邏輯未刪除值(默認為 0)

import com.baomidou.mybatisplus.annotation.*;
import lombok.Data;

import java.io.Serializable;

/**
 * 用戶訂單
 *
 * @author yunyan
 */
@TableName("t_user")
@Data
public class UserPO implements Serializable {

    /**
     * id
     */
    @TableId(type = IdType.ASSIGN_ID)
    private Long id;
    /**
     * 用戶名
     */

    private String userName;
    /**
     * 密碼
     */

    private String password;
    /**
     * 昵稱
     */

    private String nickName;
    /**
     * 刪除標識
     */
    @TableLogic
    private Integer delFlag;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.example.testinterface.entity.po.UserPO;
import org.apache.ibatis.annotations.Mapper;

/**
 * 用戶映射器
 *
 * @author yunyan
 */
@Mapper
public interface UserMapper extends BaseMapper<UserPO> {
}

/**
 * 用戶服務
 *
 * @author yunyan
 */
public interface IUserService extends IService<UserPO> {

}

/**
 * 用戶服務impl
 *
 * @author yunyan
 */
@Service
public class UserServiceImpl extends ServiceImpl<UserMapper, UserPO> implements IUserService {

}

@RequestMapping("/open/del")
    public ResultUtil del(UserParam userParam){
        UserPO one = userService.getOne(new LambdaQueryWrapper<UserPO>()
                .eq(UserPO::getUserName, userParam.getUserName()));
        boolean b = userService.removeById(one);
        System.out.println(b);
        return ResultUtil.success(b);
    }

@Data
public class ResultUtil {

    private String code;

    private String message;

    private  Object data;
    public static  ResultUtil success(Object data){
        ResultUtil resultUtil = new ResultUtil();
        resultUtil.setCode("200");
        resultUtil.setMessage("請求成功");
        resultUtil.setData(data);
        return resultUtil;
    }
}