Calculate column value and insert another table
<p>I have create two  tables <code>deposit</code> and  <code>final_balance</code>;I want to sum <code>deposit_amount</code> in <code>deposit</code> table and insert the result into <code>final_balance</code>  table.
Can I can use a trigger?</p>

<pre><code>CREATE TABLE deposit(cust_id VARCHAR2(10),loan_id VARCHAR2(10),deposit_type VARCHAR2(10),deposit_amount NUMBER(20));
INSERT INTO deposit values ('001CUS1','001LOAN1','Fixed',3500);
INSERT INTO deposit values ('001CUS2','001LOAN2','Fixed',3900);
INSERT INTO deposit values ('001CUS3','001LOAN3','Fixed',7000);
INSERT INTO deposit values ('001CUS4','001LOAN4','Fixed',28000);
INSERT INTO deposit values ('001CUS5','001LOAN5','Fixed',15200);
INSERT INTO deposit values ('001CUS6','001LOAN6','Fixed',2420);
INSERT INTO deposit values ('001CUS7','001LOAN7','Primary',2420);
INSERT INTO deposit values ('002CUS1','002LOAN1','Primary',27000);
INSERT INTO deposit values ('002CUS2','002LOAN2','Primary',20200);
INSERT INTO deposit values ('002CUS3','002LOAN3','Primary',6900);
CREATE TABLE final_balance(
total_deposit NUMBER(20)
);
</code></pre>