Question

我已经编写了一个程序来查找两个日期之间的差异，并以YYYY-MM-DD格式显示结果但遇到错误。任何人都可以帮我吗？

CREATE OR REPLACE PROCEDURE DATECALCULATOR(DATE_1 IN DATE, DATE_2 IN DATE) AS
  DATEDIFF DATE;

BEGIN
    DATEDIFF=TO_DATE(DATE_1,'YYYY-MM-DD')-TO_DATE(DATE_2,'YYYY-MM-DD');
    DBMS_OUTPUT.PUT_LINE ('Date difference is: ' || TO_DATE(DATEDIFF,'YYYY-MM-DD'));
END;
/

超出程序代码：

EXECUTE DATECALCULATOR('2017-09-10', '2010-01-01');

Answer 1

如果从其他日期中减去，则会得到这两个日期之间的天数。您无法通过to_date函数将此值转换为日期。你希望得到什么日期，例如日期之间的差异456天它的意思是：

1 year 3 month and several days

返回格式化的字符串值可能更好吗？

Answer 2

使用INTERVAL DAY TO SECOND类型将格式设为+D HH24:MI:SS.FF6：

CREATE OR REPLACE PROCEDURE DATECALCULATOR(
  DATE_1 IN DATE,
  DATE_2 IN DATE
) AS
  DATEDIFF INTERVAL DAY(9) TO SECOND;
BEGIN
  DATEDIFF= (DATE_1- DATE_2) DAY(9) TO SECOND;
  DBMS_OUTPUT.PUT_LINE('Date difference is: ' || DATEDIFF );
END;
/

或者，使用MONTHS_BETWEEN函数获取YYYY-MM-DD格式的差异：

CREATE OR REPLACE PROCEDURE DATECALCULATOR(
  range_end   IN DATE,
  range_start IN DATE
) AS
  DIFF NUMBER  := TRUNC( MONTHS_BETWEEN( DATE_1, DATE_2 ) ) - 1;
  dt   DATE    := ADD_MONTHS( range_start, diff );
  d    INTEGER := TRUNC( range_end - dt );
  dy   INTEGER := EXTRACT( DAY FROM LAST_DAY( dt ) );
  m    INTEGER;
  y    INTEGER;
BEGIN
  IF d > dy THEN
    diff := diff + 1;
    d    := d - dy;
  END IF;
  m := MOD( TRUNC( diff ), 12 );
  y := TRUNC( diff / 12 );

  DBMS_OUTPUT.PUT_LINE('Date difference is: '
    || TO_CHAR( y, '0009' ) || '-' || TO_CHAR( m, 'FM09' ) || '-' || TO_CHAR( d, 'FM09' ) 
  );
END;
/

PL / SQL：两个日期之间的差异

2 个答案: