CREATE TABLE `user_notifications` (
    `id`                BIGINT      NOT NULL AUTO_INCREMENT COMMENT '主键ID',
    `created_at`        BIGINT      NOT NULL DEFAULT 0 COMMENT '创建时间',
    `updated_at`        BIGINT      NOT NULL DEFAULT 0 COMMENT '更新时间',
    `deleted_at`        BIGINT      NOT NULL DEFAULT 0 COMMENT '删除时间（0 表示未删除）',
    `created_by`        BIGINT      NOT NULL DEFAULT 0 COMMENT '创建人',
    `updated_by`        BIGINT      NOT NULL DEFAULT 0 COMMENT '更新人',
    `deleted_by`        BIGINT      NOT NULL DEFAULT 0 COMMENT '删除人',
    `notification_uuid` VARCHAR(64) NOT NULL DEFAULT '' COMMENT '消息UUID',
    `user_id`           BIGINT      NOT NULL DEFAULT 0 COMMENT '接收用户ID',
    `msg_type`          TINYINT     NOT NULL DEFAULT 0 COMMENT '消息类型 1=点赞通知 2=订单通知 3=系统通知',
    `sender_id`         BIGINT      NOT NULL DEFAULT 0 COMMENT '发送者ID 系统消息为0',
    `title`             VARCHAR(128) NOT NULL DEFAULT '' COMMENT '消息标题',
    `content`           TEXT        COMMENT '消息内容',
    `is_read`           TINYINT     NOT NULL DEFAULT 0 COMMENT '是否已读 1=未读 2=已读',
    `read_time`         BIGINT      NOT NULL DEFAULT 0 COMMENT '阅读时间',
    PRIMARY KEY (`id`),
    UNIQUE KEY `uk_notification_uuid` (`notification_uuid`),
    KEY `idx_notifications_user_read` (`user_id`, `is_read`)
) ENGINE = InnoDB DEFAULT CHARSET = utf8mb4 COMMENT = '用户通知表';