update "Recommended IDs for New Entities" to "Using Bytes as IDs" (#614)

* update "Recommended IDs for Creating New Entities" to "Using Bytes as IDs"

* update recommended IDs

* update concatenation of IDs

* remove personal voice

Author: yash251

website/pages/en/developing/creating-a-subgraph.mdx

@@ -529,13 +529,24 @@ The second handler tries to load the existing `Gravatar` from the Graph Node sto
 
 ### Recommended IDs for Creating New Entities
 
-Every entity has to have an `id` that is unique among all entities of the same type. An entity's `id` value is set when the entity is created. Below are some recommended `id` values to consider when creating new entities. NOTE: The value of `id` must be a `string`.
+It is highly recommended to use `Bytes` as the type for `id` fields, and only use `String` for attributes that truly contain human-readable text, like the name of a token. Below are some recommended `id` values to consider when creating new entities.
 
-- `event.params.id.toHex()`
-- `event.transaction.from.toHex()`
-- `event.transaction.hash.toHex() + "-" + event.logIndex.toString()`
+- `transfer.id = event.transaction.hash`
 
-We provide the [Graph Typescript Library](https://github.com/graphprotocol/graph-ts) which contains utilities for interacting with the Graph Node store and conveniences for handling smart contract data and entities. You can use this library in your mappings by importing `@graphprotocol/graph-ts` in `mapping.ts`.
+- `let id = event.transaction.hash.concatI32(event.logIndex.toI32())`
+
+- For entities that store aggregated data, for e.g, daily trade volumes, the `id` usually contains the day number. Here, using a `Bytes` as the `id` is beneficial. Determining the `id` would look like
+
+```typescript
+let dayID = event.block.timestamp.toI32() / 86400
+let id = Bytes.fromI32(dayID)
+```
+
+- Convert constant addresses to `Bytes`.
+
+`const id = Bytes.fromHexString('0xdead...beef')`
+
+There is a [Graph Typescript Library](https://github.com/graphprotocol/graph-ts) which contains utilities for interacting with the Graph Node store and conveniences for handling smart contract data and entities. It can be imported into `mapping.ts` from `@graphprotocol/graph-ts`.
 
 ### Handling of entities with identical IDs