Ambivalent error handling

Native IndexedDB can throw an error at you in two different ways. It may throw an exception when you call its API or it may call the onerror callback if you provided such. For each request you wish to control the error behavior of, you must point out the onerror callback to your handler for that. All this makes it very cumbersome implementing a single query operation if you are concerned about programmatic safety and transaction robustness. With Dexie, each asynchronous method returns a Promise where you do not only catch error events but also exceptions. Both uncaught errors and exceptions abort the transaction and bubble up to Transaction’s Promise assuring you could never miss any error or commit a transaction by accident.

Poor queries

Native IndexedDB API has a poor set of query methods. Dexie extends the API with case insensitive queries, set matching and logical OR. It also simplifies the use of the existing IndexedDB capabilities such as reverse ordering, limiting search results, etc, accessible by writing short, simple, readable and intuitive javascript queries much similar to LINQ queries (for those of you who are familiar with that).

Not reactive

Unlike localStorage, indexedDB does not provide any native events when data is mutated. This makes it cumbersome for front-end components to react on database changes that happens in another tab, window or worker. Dexie comes with a magic helper function liveQuery() that turns normal (pull-based) queries into reactive ones which fits perfectly well in front-end components so that they re-render whenever data is mutated by the app itself, a worker or another tab.

Code complexity

Without a wrapper library like Dexie, your application code could become unnecessarily complex since you need to write much more lines of code and if correct error handling is important for you, your code will soon become very complex and hard to read and maintain.