How to select'om get the sum of all columns starting with X? (mssql)

Question

MySQL

I have a table:
id, name, a1,a2,a3,..., an
where a1-an is in decimal format, null is possible.
n - arbitrary number (the number of columns may change over time)
I would like to get the sum of all columns starting with 'a' in one query, for example:
table:
2 milk 1 3 5
3 meat 5 6 2
Select id, sum
2 9
3 13
Thank you.

Answer 1

Normalize the base and get rid of the crooked storage method. Move the quantity of goods in stores to a separate table (`product id`, `shop id`, `quantity`).

Answer 2

Use CONCAT()