Question

We have 2 very simple SELECT statements:

SELECT value from table where date between DATE1 and DATE2
SELECT value from table where date between DATE3 and DATE4

We need a way to write a single SQL statement which will get the difference of the “value” that is returned from these two SQL statements.

We tried the following but it was not successful:

SELECT value from table where date between DATE1 and DATE2
minus 
SELECT value from table where date between DATE3 and DATE4

Any suggestion is highly appreciated.

Answer 1

Untested but should work:

SELECT
    (SELECT value from table where date between DATE1 and DATE2) - 
    (SELECT value from table where date between DATE3 and DATE4)
FROM dual;

Assuming that your SELECT value is guaranteed to return a single value