如何使用 postgresql/netezza 从日期时间中减去天数或月数
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how to subtract days or months from datetime using postgresql/netezza
提问by moe
I have this sql query that is working fine but would like to convert it into some kind of postgresql or netezza equivalent query. Here are my queries:
我有这个运行良好的 sql 查询，但想将其转换为某种 postgresql 或 netezza 等效查询。以下是我的疑问：
SELECT name, location, Date FROM myTable WHERE [Date] < DateAdd(hh, 48, [shipDate]
and other query
和其他查询
SELECT name, location, Date FROM myTable WHERE [Date] < DateAdd(d, 90, [shipDate]
采纳答案by ScottMcG
For Netezza the easiest thing to do is use an interval calculation:
对于 Netezza，最简单的方法是使用间隔计算：
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';
You can also use add_months if you want to do month calculations that are aware of the different length of the months.
如果要进行了解月份不同长度的月份计算，也可以使用 add_months。
SELECT name, location, Date FROM myTable WHERE Date < add_months(shipdate, 3);
