I want to do DynamoDB query items with multiple filters something like: latest post(createdAt), country (According to user country), ByuserId, with specific tag
Is this possible?

Question

My items in DynamoDB table is according to this model:
```
type Post @model{
I'd: ID
content: string
Country: string
Tag: [string]
ByuserId:ID!
Createdat:AWSdate
}
```
I want mutiple filter like specifictag, specific time, by specific user,post with specific country.

Like YouTube feed most posts are: chennal you subscribed, tags that are related to watch history, posts are mainly from current user country , and they promote latest post

Answer

You can specify multiple filters using a [`FilterExpression`](https://docs.aws.amazon.com/amazondynamodb/latest/APIReference/API_Scan.html#DDB-Scan-request-FilterExpression), however it is highly in-efficient and best to be avoided:

```
FilterExpression="specifictag=123 AND specifictime=92487109247"
```

To make things more efficient you can make use of overloading your keys, or using composite keys. For example, if you always want to filter based on the same attributes in order, then you can define your schema to suit that. This makes our query calls highly efficient, but can take some thought to get the schema design correct

| pk | sk | data |
| --- | --- | --- |
| user123 | dynamodb#2022-10-21#Ireland | Data |

```
KeyConditionExpression="pk=user123 AND sk=dynamodb#2022-10-21#Ireland"
```

Answer

Check this out https://stackoverflow.com/questions/58253219/dynamodb-how-to-design-and-query-multiple-fields

I want to do DynamoDB query items with multiple filters something like: latest post(createdAt), country (According to user country), ByuserId, with specific tag Is this possible?

Contenuto pertinente