返回类型为字符串,使用NVL()函数
SELECT nvl(t2.codetypename,‘没找到’) aa
/* INTO szchannelname*/
FROM sl_codetypedef t2
WHERE t2.codetype = ‘CHANNEL’ AND t2.codetypeno = ‘98’;
这样的话,无法返回结果,如图:
将引用改为:nvl(select from)外面
SELECT nvl( (SELECT t2.codetypename
FROM sl_codetypedef t2
WHERE t2.codetype = ‘CHANNEL’ AND t2.codetypeno = ‘98’ and rownum=1),‘没找到’) FROM DUAL;