{
    "summary": [
        {
            "name": "voucher_usage_log",
            "title": "代金券使用流水",
            "primary": ["id"],
            "catelog": "entity"
        }
    ],
    "fields": [
        {"name": "id", "title": "主键ID", "type": "str", "length": 32, "nullable": "no"},
        {"name": "instance_id", "title": "券实例ID", "type": "str", "length": 32, "nullable": "no"},
        {"name": "customer_id", "title": "客户ID", "type": "str", "length": 32, "nullable": "no"},
        {"name": "order_id", "title": "订单/消费ID", "type": "str", "length": 64, "nullable": "no"},
        {"name": "face_value", "title": "券面值", "type": "double", "length": 10, "dec": 2, "nullable": "no"},
        {"name": "deducted_amount", "title": "实际抵扣金额", "type": "double", "length": 10, "dec": 2, "nullable": "no"},
        {"name": "used_at", "title": "使用时间", "type": "datetime", "nullable": "no"},
        {"name": "used_by", "title": "操作人", "type": "str", "length": 32, "nullable": "yes"},
        {"name": "product_type", "title": "产品类型", "type": "str", "length": 32, "nullable": "yes"},
        {"name": "product_name", "title": "产品名称", "type": "str", "length": 64, "nullable": "yes"}
    ],
    "indexes": [
        {"name": "idx_log_instance", "idxtype": "index", "idxfields": ["instance_id"]},
        {"name": "idx_log_customer", "idxtype": "index", "idxfields": ["customer_id"]},
        {"name": "idx_log_order", "idxtype": "index", "idxfields": ["order_id"]}
    ],
    "codes": [
        {
            "field": "instance_id",
            "table": "voucher_instance",
            "valuefield": "id",
            "textfield": "code"
        }
    ]
}