Lines to columns with different date ranges

Question

I'm having issues using (T-)SQL converting data that is given in this format...

Group   Column      Value   ValidFrom   ValidTo
1       LowerBorder 150000  25.09.2018  31.12.2999
1       LowerBorder 0       13.09.2018  25.09.2018
1       LowerBorder 150000  08.09.2018  13.09.2018
1       LowerBorder 0       07.09.2018  08.09.2018
1       UpperBorder 450000  08.09.2018  31.12.2999
1       UpperBorder 0       07.09.2018  08.09.2018
2       LowerBorder 5       08.09.2018  31.12.2999
2       UpperBorder 7       08.09.2018  31.12.2999

to this format:

Group   LowerBorder UpperBorder ValidFrom   ValidTo
2       5           7           08.09.2018  31.12.2999
1       150000      450000      25.09.2018  31.12.2018
1       0           450000      13.09.2018  25.09.2018
1       150000      450000      08.09.2018  13.09.2018
1       0           0           07.09.2018  08.09.2018

To explain, let's have a look at the two lines in Group 1 that both have a "ValidFrom" date of 07.09.2018 in the first table. Putting these together, we get the line at the bottom of the second table. This is the easy case because they have the same "ValidTo" date.

However, if you look at the two lines in Group 1 that have a date of 08.09.2018 -> one of them has a ValidTo date of 13.09.2018 and the other has a ValidTo date of 31.12.2999. So the value of the second line (which relates to "UpperBorder") is valid "until the end" but there will be more lines for the "LowerBorder" before "the end". I'm having a hard time creating the lines in table 2 because of that.

I'm pretty sure I have to use the PIVOT-function as the second step but I'm missing the first step... I have a hunch that I have to somehow create new lines for combinations of "Column" and "ValidFrom" first and then copy the values to the new lines... but I might be mistaken.

Answer 1

Ok, I am not sure if this is going to work...

select *
from Table1 a
pivot
(
 min([Value])
 FOR [Column] in (LowerBorder, UpperBorder)
) as b