SQL query result Merging

-10 ~ Number of positive integers between 10

I use

Declare @ A int
Set @ A =-10
If (@ a between-10 and 10)
Begin
While (@ A <= 10)
Begin
Select @ A, case when @ a> 0 then 1
Else 0
End as 'y'
Set @ A = @ A + 1
End
End

The following results are displayed:
Y
----------------------
-10 0

(One row is affected)

Y
----------------------
-9 0

(One row is affected)

Y
----------------------
-8 0

(One row is affected)

Y
----------------------
-7 0

(One row is affected)

Y
----------------------
-6 0

(One row is affected)

Y
----------------------
-5 0

(One row is affected)

Y
----------------------
-4 0

(One row is affected)

Y
----------------------
-3 0

(One row is affected)

Y
----------------------
-2 0

(One row is affected)

Y
----------------------
-1 0

(One row is affected)

Y
----------------------
0 0

(One row is affected)

Y
----------------------
1 1

(One row is affected)

Y
----------------------
2 1

(One row is affected)

Y
----------------------
3 1

(One row is affected)

Y
----------------------
4 1

(One row is affected)

Y
----------------------
5 1

(One row is affected)

Y
----------------------
6 1

(One row is affected)

Y
----------------------
7 1

(One row is affected)

Y
----------------------
8 1

(One row is affected)

Y
----------------------
9 1

(One row is affected)

Y
----------------------
10 1

(One row is affected)

The results are separated and sum operations are not allowed. How can I merge the results with Union all?

There is

@ Value % 2 = 0? "Even": "odd"

How to query

When I add select to the front, a syntax error is prompted near '=.

Thank you.