关于字串的问题
begin
--grade and grade_flag
begin
if(cc.grade='Z' and cc.grade_flag='N') then
B:='_Z';
elsif(cc.grade='P' and cc.grade_flag='N') then
B:='_P';
elsif(cc.grade='N' and cc.grade_flag='N') then
B:='_N';
elsif(cc.grade='V' and cc.grade_flag='N') then
B:='_V';
elsif(cc.grade='P' and cc.grade_flag='Y') then
B:='_Z'||'_P';
elsif(cc.grade='N' and cc.grade_flag='Y') then
B:='_Z'||'_P'||'_N';
elsif(cc.grade='V' and cc.grade_flag='Y') then
B:='_Z'||'_P'||'_N'||'_V';
end if;
end;
在这段程序中当cc.grade='V' and cc.grade_flag='Y'时B是不是('_Z','_P','_N','_V')啊?