如何使用postgresql/netezza從日期時間中減去幾天或幾個月

Question

我有這個SQL查詢工作正常，但想將其轉換成某種postgresql或netezza等效查詢。這裏是我的查詢：

SELECT name, location, Date FROM myTable WHERE [Date] < DateAdd(hh, 48, [shipDate] 

等查詢

SELECT name, location, Date FROM myTable WHERE [Date] < DateAdd(d, 90, [shipDate] 

Answer 1

致Netezza公司最容易做的事情是使用間隔計算：

SELECT name, location, Date FROM myTable WHERE Date < shipDate + interval '48 hours'; 
SELECT name, location, Date FROM myTable WHERE Date < shipDate + interval '2 days'; 
SELECT name, location, Date FROM myTable WHERE Date < shipDate + interval '90 days'; 

，如果你願意，你也可以使用ADD_MONTHS做月份計算，瞭解月份的不同長度。

SELECT name, location, Date FROM myTable WHERE Date < add_months(shipdate, 3);