Using transaction on a single update statement

Question

I am dubbing some SP at work and I have discover that whoever wrote the code used a transaction on a single update statement like this

begin transaction 
*single         


        

Answer 1

I understand that this is wrong because transaction is used when you want to update multiple tables.

Not necessarily. This involves one table only - and just 2 rows:

--- transaction  begin

BEGIN TRANSACTION ;

UPDATE tableX 
SET Balance = Balance + 100
WHERE id = 42 ;

UPDATE tableX 
SET Balance = Balance - 100
WHERE id = 73 ;

COMMIT TRANSACTION ;

--- transaction  end