本文為您介紹如何使用DATEDIFF函數(shù)，計算兩個日期之間的天數(shù)差值。

使用限制

僅實時計算引擎VVR 3.0.0及以上版本支持DATEDIFF函數(shù)。

語法

INT DATEDIFF(VARCHAR enddate, VARCHAR startdate)
INT DATEDIFF(TIMESTAMP enddate, VARCHAR startdate)
INT DATEDIFF(VARCHAR enddate, TIMESTAMP startdate)
INT DATEDIFF(TIMESTAMP enddate, TIMESTAMP startdate)

入?yún)?/h2>
參數(shù) 數(shù)據(jù)類型
startdate TIMESTAMP、VARCHAR
enddate TIMESTAMP、VARCHAR
說明
  • VARCHAR日期格式：yyyy-MM-dd或yyyy-MM-dd HH:mm:ss。
  • 如果入?yún)⒅腥魏我粋€為NULL或解析錯誤，則返回為NULL。

示例

  • 測試數(shù)據(jù)
    datetime1(VARCHAR) datetime2(VARCHAR) nullstr(VARCHAR)
    2017-10-15 00:00:00 2017-09-15 00:00:00 NULL
  • 測試語句 
    SELECT  DATEDIFF(datetime1, datetime2) as int1, 
        DATEDIFF(TIMESTAMP '2017-10-15 23:00:00',datetime2) as int2, 
        DATEDIFF(datetime2,TIMESTAMP '2017-10-15 23:00:00') as int3, 
        DATEDIFF(datetime2,nullstr) as int4, 
        DATEDIFF(nullstr,TIMESTAMP '2017-10-15 23:00:00') as int5, 
        DATEDIFF(nullstr,datetime2) as int6, 
        DATEDIFF(TIMESTAMP '2017-10-15 23:00:00',TIMESTAMP '2017-9-15 00:00:00')as int7
FROM T1;
  • 測試結果
    int1(INT) int2(INT) int3(INT) int4(INT) int5(INT) int6(INT) int7(INT)
    30 30 -30 NULL NULL NULL 30