How to reset auto_increment id in mysql using nestjs - mysql

Question

I have a feed table that contains id, body, created_at fields. When I send Post() on postman after Delete() method the id for the feed table auto_increments as if a record has not been deleted. I am unsure how to rectify this, I am using MySql database, nestjs and TypeORM for the backend.
feed controller.ts
#Controller("feed")
export class FeedController {
constructor(private feedService: FeedService) {}
#Post()
createNewPost(#Body() feedPost: HomeFeedDto): Observable<HomeFeedDto> {
return this.feedService.createPost(feedPost);
}
#Get()
allPosts(): Observable<HomeFeedDto[]> {
return this.feedService.getAllPosts();
}
//api delete method
#Delete(":id")
// delete home feed post by id
deleteFeedPost(#Param("id") id: number): Observable<DeleteResult> {
return this.feedService.deletePost(id);
}
}

Answer 1

This is just the way that auto incrementing columns work in a database. Once a record has been created that uses a particular id value it can never be used again, even if the record that owned it was deleted.
What would you expect to happen in the case where there were many records? If the current incrementing id was 1000 and then you deleted the record with id = 1 would you expect that the next time you inserted a record it would be given id = 1 again instead of id = 1001?
There are lots of practical reasons why re-using a previously issued id would be very bad for business logic especially if anyone who is a consumer of your API has a cached version of the old record.
If you really want to achieve this behavior you would have to look at writing custom functions either inside of the database or your API which check to see if any ids are missing from sequence and then manually assign your own IDs instead of letting the database do it. I would highly recommend you don't do this though as the behavior you're seeing is designed like that for a reason.