oracle将blob类型转换成varchar类型做查询条件查询
SELECT RULE_INFO FROM DYNAMIC_CHECK_CFG
where Utl_Raw.Cast_To_Varchar2(Dbms_Lob.Substr(RULE_INFO)) like '%select%'；

RULE_INFO 为blob类型

转换字符串函数： Utl_Raw.Cast_To_Varchar2(Dbms_Lob.Substr(RULE_INFO))