Thanks for the good question. 🙂
wish to see more like this.
(I guess this depends on the initial type of the data which in the first position.
For this "select '130'+'120'+1" it will give you 130121, but for this "select 1+'120'+'130'" it will give you 251 not 121130. It takes the next value and it converts to the first value's data-type and then so on...
select 0 + '130'+'120'+1 - this gives 251 (because the initial value type is number and it works for only int type)
select 0 + '130'+'120'+2.56 - and the decimal works only with the end value.)
The first and the hardest SQL statement I have wrote- "select * from customers" - and I was happy and felt smart.