我爱java系列---【在字符数组中查询某个字符串是否存在】
作者:互联网
mysql中的FIND_IN_SET函数
需求:根据省份id,查询可以在该省份下发信息的通道id
sql语句:
SELECT cpa.CHANNEL_ID id FROM channel_price_batch cpa WHERE ( SELECT FIND_IN_SET( '021', cpa.PROVINCE_ID_LIST ) AS a ) > 0 //若‘021’在一条记录中存在,则a=1;若在多条记录中存在,有几条a就等于几 #GROUP BY cpa.CHANNEL_ID //把查询结果去重,只显示一条 ORDER BY cpa.CREATE_TIME DESC,cpa.ID DESC //按创建时间降序排序,若创建时间一样,就按id降序排序
项目中用的:
<select id="findPageByProvinceId" resultType="java.util.Map">
SELECT
c.ID id,
c.NAME name,
c.SP_ID spId,
c.SERVER_IP serverIp,
c.SERVER_PORT serverPort,
c.PROTOCOL_TYPE protocolType,
c.SERVICE_ID serviceId,
c.PROVINCE_ID provinceId,
c.STATUS status
FROM
channel c
left outer join channel_price_batch cpa on cpa.CHANNEL_ID = c.ID
where (SELECT FIND_IN_SET(#{provinceId}, cpa.PROVINCE_ID_LIST) AS a)>0
GROUP BY c.ID //去重
ORDER BY c.CREATE_TIME DESC,c.ID DESC //按创建时间降序排序,若创建时间一样,就按id降序排序
</select>
查询结果:
标签:字符,java,cpa,降序,ID,字符串,id,SELECT,DESC 来源: https://www.cnblogs.com/hujunwei/p/12161555.html