Question

select replace(stuff('123456',2,2,'ABCD'),'1',' ')

select LEFT('ABCD456',4)

select left(replace(stuff('123456',2,2,'ABCD'),'1',' '),4)

Ok now the first select outputs ‘ABCD456’, the series of functions evaluates to that
exactly the first parameter to the left function in the second select
second select returns ‘ABCD’ as expected
third select returns ‘ABC’

Why? Shouldn’t it also output ‘ABCD’?
Does anybody know?
Thanks in advance.

Answer 1

It is clearer if you do

select '[' + left(replace(stuff('123456',2,2,'ABCD'),'1',' '),4) + ']'

which returns

[ ABC]

There is a leading space!

select stuff('123456',2,2,'ABCD') Gives 1ABCD456

Then you replace the 1 with a space