sql

I need to get the annual revenue for Transfer prospects(defined by alliance_member_classification = 'TPR')

for this I need to join 2 tables such as:
fh_history(business_id, history_trans_id, campaign_history_date, campaign_nbr, annual_revenue)
allaince_history(business_id, contact_id, alian_id, campaign_nbr,fedex_acct_nbr,  alliance_member_classification )


where prospect_id ( is defined as business_id + contact_id - one business can have multiple contact_ids and one alliance can have
mulitple prospects. One campaign can have only many prospects.

Revenue should not be double counted..
for example:
business_id   contact_id   fedex_acct_nbr    annual_revenue
 5             12            1                  5000
 5             13            1                  5000  
 5             14            1                  5000


one business has multiple contacts . so in above example the annual reveue shoule be 5000 and not 15000