如何将多个图像 URL 添加到 Cloud Firestore 中的同一字段

Question

I am new to coding and I am looking for a solution to add multiple image URLs (the images are selected from the gallery) to the same field in Cloud Firestore so as I could retrieve and display them later in a ViewPager .

I have been trying to find the solution, but with no luck.

Please, help me.

Thank you in advance.

Answer 1

您可以通过将 json 数组存储在 cloud_firestore image_url_key {"array": ["url1","url2","url3"]} 中来尝试

Answer 2

There are two ways in which you can achieve this. The first one would be to store those urls in a map . In this case the database structure should look this:

Firestore-root
   |
   --- collection
         |
         --- document
               |
               --- urls
                    |
                    --- url : "http://..."
                    |
                    --- url : "http://..."

But because the urls contain characters that aren't allowed to be used in the keys, you'll need to use an encoded version of the URL as the key (typically just strips the illegal characters, but a hashcode is also common) and then use the full URL as the value.

Because from 13th august it is possible to filter data in Cloud Firestore based on array values using whereArrayContains() , the second solution would be to store those urls in an array. In this case the database structure should look this:

Firestore-root
   |
   --- collection
         |
         --- document
               |
               --- urls: ["http://...", "http://..."]