declare
i long:=19990101;
s varchar2(8);
d date;
begin
s := TO_CHAR(i);
d := TO_DATE(s,'YYYYMMDD');
dbms_output.put_line(to_char(d,'YYYY-MM-DD'));
end;
i long:=19990101;
s varchar2(8);
d date;
begin
s := TO_CHAR(i);
d := TO_DATE(s,'YYYYMMDD');
dbms_output.put_line(to_char(d,'YYYY-MM-DD'));
end;
NUMBER->CHAR
CHAR->DATE
DATE->CHAR
CHAR->NUMBER不可以:
NUMBER->DATE
DATE->NUMBER所以需要中间转换.