原始数据:
第一种:使用case when判断
SELECT username AS virtualCardNum, realname AS realName, authenticated AS SMZ, ( CASE WHEN idnumber IS NULL THEN '' WHEN idnumber = "1" THEN "0" ELSE idnumber END ) AS encIdNumber FROM appuser WHERE realname = "测试王宁"
第二种:
使用IFNULL函数