#### Update customer balance field when new purchase is made

Write a trigger that updates a customer's balance field in a customer table whenever a new purchase is made, using data from a purchase table.

#### Problem

```Given a table of customer data, write a trigger that will automatically update the customer's balance field whenever a new purchase is made.
Input:
Table: customer
id name balance
1 John 100
2 Jane 200
3 Joe 300
4 Jill 400
5 Jake 500
Table: purchase
id customer_id amount
1 1 10
2 2 20
3 3 30
4 4 40
5 5 50
Output:
Table: customer
id name balance
1 John 110
2 Jane 220
3 Joe 330
4 Jill 440
5 Jake 550```

#### Solution

This solution is in SQL. Our A.I. can create solutions in multiple languages.
```CREATE TRIGGER update_balance
AFTER INSERT ON purchase
FOR EACH ROW
BEGIN
UPDATE customer
SET balance = balance + NEW.amount
WHERE id = NEW.customer_id;
END;

/*

The trigger is optimal because it is only executed when a new purchase is made.

*/```

A.I. Evaluation of the Solution

The trigger will automatically update the customer's balance field whenever a new purchase is made, which is the desired outcome. The approach is sound and the trigger is executed only when needed, so this is a good solution.

Evaluated at: 2022-11-14 02:15:33