函数：
 1 create or replace function fn_test(tablename in varchar2) return number is
 2   sqls varchar2(100);
 3   rtn number(10):=0;
 4 begin
 5   --获取学生表的记录条数
 6  --select count(*) into rtn from student;
 7  
 8   sqls:=‘select count(*) from ‘ || tablename;
 9   execute immediate sqls into rtn;
10   dbms_output.put_line(‘记录条数 rtn=‘|| rtn);
11   return(rtn);
12 end fn_test;

1 select fn_test(‘student‘) from dual;