How to use Vercel KV to store and retrieve posts from an api? about edge-config HOT 6 CLOSED

If you want to remove all the keys from your database, you can use FLUSHDB. Careful though, this will permanently delete all data in the cache!

await kv.flushdb()

from edge-config.

Hi @xts-bit, generally we try to use our Github issues as a place to track bugs and feature requests. For general help requests, you might get a response quicker in the Vercel Community Discussions or from the Vercel Support.

To answer your question, in your route handler, you would first check if the data your user is requesting is already in the cache via kv.get. If it is and your happy the data is still fresh, you can return it from your handler via res.json and skip hitting your database. If the data is not in the cache, you fetch it from the database, set it in the cache and then return it to the user via res.json. You can optionally set a Time-to-live (TTL) on the data in your cache so it doesn't persist forever and you don't serve your users stale data indefinitely. The cache key for your data should be composed of the input you give to the handler so that you don't return the same response for different input (e.g. page).

Your code might look something like this:

+import { kv } from "@vercel/kv";

 router.get('/posts', async (req, res) => {
     try {
         const page = Number(req.query.page) || 1; 
         const limit = Number(req.query.limit) || 50;
+        const cacheKey = `posts-${page}-${limit}`;
+        const cachedValue = await kv.get(cacheKey);
+
+        if (cachedValue) {
+            return res.json(cachedValue);
+        }
 
         const skip = (page - 1) * limit;
         const result = await User.aggregate([
             { $project: { posts: 1 } },
             { $unwind: '$posts' },
             { $project: { postImage: '$posts.post', date: '$posts.date' } },
             { $sort: { date: -1 } },
             { $skip: skip },
             { $limit: limit },
         ]);
 
+        await kv.set(cacheKey, result);
 
         res.json(result);
     } catch (err) {
         console.error(err);
         res.status(500).json({ message: 'Internal server error' });
     }
 });

Since we don't have any bug or feature request here, I'm going to close this out. Thanks for using KV.

from edge-config.

@adriancooney Thanks Adrian, Any idea How to delete all the cache from kv?

from edge-config.

@adriancooney Is ttl is set like this? await kv.set(cacheKey, result, { ttl: 100 });

from edge-config.

@adriancooney Is ttl is set like this? await kv.set(cacheKey, result, { ttl: 100 });

await kv.set('setExample', '123abc', { ex: 100, nx: true });

Options

The SET command supports a set of options that modify its behavior:

• EX seconds -- Set the specified expire time, in seconds.
• PX milliseconds -- Set the specified expire time, in milliseconds.
• EXAT timestamp-seconds -- Set the specified Unix time at which the key will expire, in seconds.
• PXAT timestamp-milliseconds -- Set the specified Unix time at which the key will expire, in milliseconds.
• NX -- Only set the key if it does not already exist.
• XX -- Only set the key if it already exists.
• KEEPTTL -- Retain the time to live associated with the key.
• GET -- Return the old string stored at key, or nil if key did not exist. An error is returned and SET aborted if the value stored at key is not a string.

from edge-config.

@adriancooney Is ttl is set like this? await kv.set(cacheKey, result, { ttl: 100 });

await kv.set('setExample', '123abc', { ex: 100, nx: true });

Options

The SET command supports a set of options that modify its behavior:

• EX seconds -- Set the specified expire time, in seconds.
• PX milliseconds -- Set the specified expire time, in milliseconds.
• EXAT timestamp-seconds -- Set the specified Unix time at which the key will expire, in seconds.
• PXAT timestamp-milliseconds -- Set the specified Unix time at which the key will expire, in milliseconds.
• NX -- Only set the key if it does not already exist.
• XX -- Only set the key if it already exists.
• KEEPTTL -- Retain the time to live associated with the key.
• GET -- Return the old string stored at key, or nil if key did not exist. An error is returned and SET aborted if the value stored at key is not a string.

Hello, is there no option like this for hset? I'd like to do what the op was talking about, setting TTL for the whole hash assigned to the key.

from edge-config.