package com.example.caseData.dao;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.example.caseData.model.CaseExchangeVoteModel;
import com.example.caseData.model.CaseExchangeVoteOptionModel;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Update;

@Mapper
public interface CaseExchangeVoteOptionDao extends BaseMapper<CaseExchangeVoteOptionModel> {
    /**
     * Inc 自增
     * @param optionId 文章 ID
     * @param field     字段名称
     * @param numeral   增加的数值
     * @return 更新的行数
     */
    @Update("UPDATE case_exchange_vote_option SET ${field} = ${field} + #{numeral} WHERE option_id = #{optionId}")
    int inc(@Param("optionId") Long optionId, @Param("field") String field, @Param("numeral") int numeral);

    /**
     * Dec 自减
     *
     * @param optionId 文章 ID
     * @param field     字段名称
     * @param numeral   减少的数值
     * @return 更新的行数
     */
    @Update("UPDATE case_exchange_vote_option " +
            "SET ${field} = CASE WHEN ${field} >= #{numeral} THEN ${field} - #{numeral} ELSE 0 END " +
            "WHERE option_id = #{optionId}")
    int dec(@Param("optionId") Long optionId, @Param("field") String field, @Param("numeral") int numeral);
}