tbl1: contract

| c_ssn | m_ssn | termination |
===============================
|   1   |   1   |      Y      |
|   2   |   2   |      N      |
|   3   |   1   |      Y      |

tbl2: member

| m_ssn | count |
=================
|   1   |       |
|   2   |       |

tbl2: member

| m_ssn | count |
=================
|   1   |   2   |
|   2   |   0   |

update member
set count =
(select count(*) from contract
where contract.m_ssn = member.m_ssn & contract.termination = "Y")