Page 32 - SQL

Query

SELECT Id, Date1, Date2
FROM YourTable
ORDER BY CASE
WHEN COALESCE(Date1, '1753-01-01') < COALESCE(Date2, '1753-01-01') THEN Date1
ELSE Date2
END

Results

Id Date1 Date2

1 2017-01-01 2017-01-31

3 2017-01-31 2017-01-02

2 2017-01-31 2017-01-03

6 2017-01-04 2017-01-31

5 2017-01-31 2017-01-05

4 2017-01-06 2017-01-31

Explanation

As you see row with Id = 1 is first, that because Date1 have lowest record from entire table 2017-
01-01, row where Id = 3 is second that because Date2 equals to 2017-01-02 that is second lowest
value from table and so on.

So we have sorted records from 2017-01-01 to 2017-01-06 ascending and no care on which one
column Date1 or Date2 are those values.

Read CASE online: https://riptutorial.com/sql/topic/456/case

https://riptutorial.com/ 14