--assume x is a clob field
--x is null
--x equal to empth_clob, dbms_lob.getlength(x) = 0
select*from a where x isnullor dbms_lob.getlength(x) =0
DBMS_LOB为专门处理大对象的一个包
DBMS_LOB.GETLENGTH是查大对象数据类型的大小
--assume x is a clob field
--x is null
--x equal to empth_clob, dbms_lob.getlength(x) = 0
select*from a where x isnullor dbms_lob.getlength(x) =0
DBMS_LOB为专门处理大对象的一个包
DBMS_LOB.GETLENGTH是查大对象数据类型的大小