Querying all the values from a StorageMap

how to query all the values of a StorageMap without passing the key?

https://docs.substrate.io/rustdocs/latest/frame_support/storage/trait.StorageMap.html#tymethod.get

With that trait alone it might not be possible to do anything if you don't have a key you can pass.

I'm not sure what exactly you mean by "query", also perhaps you're working with some concrete type that merely implements the StorageMap<K, V> trait, in which case the concrete type may offer additional API.

query i meant i want to fetch all the values of that storage map irrespective of a key