Addition (Sum) Of Column Data

I am trying to build the code that will add a specific column's column where something = something

Example

ID Name Amount
1 Bill 10.00
3 Ted 15.00
1 Bill 25.00
1 Bill 35.00
4 Jude 5.00

In basic word terms, this will describe what I am seeking:

SUM(amount column where ID = 1) ..... answer would be 70.00

I am already connected to the database and can pull out one specific field in a column, just can not add that column.