代码如下:SELECT IF(AVG(cai.conversionsRate) IS NULL,0,AVG(cai.conversionsRate)) AS conversionsRate FROM campaign_info cai WHERE insertTime BETWEEN ‘2011-02-01’ AND ‘2011-02-04’ AND googleCampaignId=23331401 您可能感兴趣的文章:mysql not in、left join、IS NULL、NOT EXISTS 效率问题记录MySQL查询空字段或非空字段
