I have a relational database with 2 tables. The primary and the secondary as shown. If you add up the hours worked in the secondary table for Smith  it is 24  so hours in the primary table = 24

id       surname    hours

100     smith        24

id           Work           Hours

100    McDonalds       10

200    BMW                  6

100    Google                8

100    Microsoft             6

300    Oracle                 5

Any help would be appreciated.

Terry