如何按特定列进行分组和保留

SELECT category, COUNT(*) as count
FROM orders
GROUP BY category;

orders = [
    {"category": "A", "amount": 100},
    {"category": "B", "amount": 200},
    {"category": "A", "amount": 150},
    {"category": "B", "amount": 300}
]

grouped_orders = {}
for order in orders:
    category = order["category"]
    amount = order["amount"]
    if category not in grouped_orders:
        grouped_orders[category] = []
    grouped_orders[category].append(amount)

for category, amounts in grouped_orders.items():
    total_amount = sum(amounts)
    print(f"Category: {category}, Total Amount: {total_amount}")