函数在此：
create or replace function first_digit(v_char varchar2)
return Boolean IS
BEGIN
IF(substr(v_char,1,1) IN (*0*,*1*,*2*,*3*,*4*,*5*,*6*,*7*,*8*,*9*)) THEN
RETURN true;
ELSE
RETURN false;
END IF;
EXCEPTION
WHEN OTHERS THEN
RETURN false;
END;

select (case when first_digit(*jile*) then 1 else 0 end) t from dual
ORA-00920: 无效的关系运算符

select * from employee where first_digit(*5seo*)
同样的报错

求大神指教