uni-clientdb 轮播图 渲染banner为什么失败呢？

使用下面的代码渲染为空白：

<template>  
    <view>  
        <uni-clientdb v-slot:default="{data, loading, error, options}" collection="opendb-banner" field="image_url" where="category_id=='index_banner'">  
            <swiper :indicator-dots="true" :autoplay="true" :interval="3000" :duration="1000" :circular="true">  
                <swiper-item v-for="item in data">  
                    <view class="banner-image" :key="item._id">  
                        <image :src="item.image_url" class="banner-image"></image>  
                    </view>  
                </swiper-item>  
            </swiper>  
        </uni-clientdb>  
    </view>  
</template>

然后我在轮播图下面加了一个展示图片的代码，轮播图居然渲染出来了：

<template>  
    <view>  
        <uni-clientdb v-slot:default="{data, loading, error, options}" collection="opendb-banner" field="image_url" where="category_id=='index_banner'">  
            <swiper :indicator-dots="true" :autoplay="true" :interval="3000" :duration="1000" :circular="true">  
                <swiper-item v-for="item in data">  
                    <view class="banner-image" :key="item._id">  
                        <image :src="item.image_url" class="banner-image"></image>  
                    </view>  
                </swiper-item>  
            </swiper>  
            <view v-for="(item,index) in data" :key="index">  
                <image :src="item.image_url" class="banner-image"></image>  
            </view>  
        </uni-clientdb>  
    </view>  
</template>  
···