在SQL中：如何找到两个日期值，第二个日期值从第一个开始时开始？

Question

I am trying to run an SQL query to find (and unite) two entries of dates where the second date starts after a short term, eg x, after the first date ends.

The data in my table consists (among other columns) of two date columns: added and removed. I am comparing the entries with a copy of the table Joined with the original

SELECT *
FROM table
LEFT JOIN table AS table2 ON table.id=table2.id AND table.removed<table2.added

With this code, I can get all the entries that don't overlap each other. How can I add another criteria to define a peroid x that only gives me the not overlapping dates which are inside a range of x. So something like " table2.removed - table.added <= x".

Best would be to unite these rows to one if the above critera fits.

EDIT: sample table data and the result

id          added                 removed
1           2009-03-11 23:27:58   2017-01-28 04:45:20
1           2017-01-31 05:07:10   2018-01-22 14:14:11

So eg I want to detect this row with x < 5 days.

Answer 1

Date functions are notoriously database specific. But here is the idea using standard syntax:

SELECT *
FROM table t LEFT JOIN
     table t2
     ON t.id = t2.id AND
        t2.added > t.remove and
        t2.added < t.remove + interval '5 day'  -- whatever value you want