こういうのが書きたいとき、たとえば、 create or replace PROCEDURE tekitou( p_char_val1 VARCHAR2, p_char_val2 VARCHAR2, p_char_val3 VARCHAR2, p_char_val4 VARCHAR2 ) IS BEGIN IF (p_char_val1 = '') is null THEN IF (p_char_val2 = '') is null TH…