可以直接truncate table
模式下所有表的话可以拼接一下，比如
select ‘truncate table ‘||table_name||’;’ from SYS.USER_TABLES;

declare
tab varchar2(128);
cunt number;
cuntsql varchar2(128);
cursor c_tname is select table_name from user_tables;
begin
open c_tname;
loop
fetch c_tname into tab;
exit when c_tname%notfound;
cuntsql := 'select count(*) from '||tab;
execute immediate cuntsql into cunt;
if cunt > 0 then
execute immediate 'truncate table '||tab;
end if;
end loop;
close c_tname;
end;
/