QueryCache

Defined in: packages/query-core/src/queryCache.ts:122

The QueryCache is the storage mechanism for TanStack Query. It stores all the data, meta information, and state of the queries it contains.

Normally, you will not interact with the QueryCache directly and instead use a QueryClient for a specific cache. You can subscribe to it (inherited from Subscribable) to be informed of safe/known updates to the cache, such as queries being added, removed, or updated — updates made outside of the cache's own tracked mechanisms (e.g. mutating a query's state object directly) do not notify subscribers.

Example#

const unsubscribe = queryCache.subscribe((event) => {
  console.log(event.type, event.query)
})

Extends#

• Subscribable<QueryCacheListener>

Constructors#

Constructor#

new QueryCache(config: QueryCacheConfig): QueryCache;

Defined in: packages/query-core/src/queryCache.ts:125

Parameters#

config#

QueryCacheConfig = {}

Returns#

QueryCache

Overrides#

Subscribable<QueryCacheListener>.constructor

Properties#

config#

config: QueryCacheConfig = {};

Defined in: packages/query-core/src/queryCache.ts:125

Methods#

build()#

build<TQueryFnData, TError, TData, TQueryKey>(
   client: QueryClient, 
   options: WithRequired<QueryOptions<TQueryFnData, TError, TData, TQueryKey, never>, "queryKey">, 
state?: QueryState<TData, TError>): Query<TQueryFnData, TError, TData, TQueryKey>;

Defined in: packages/query-core/src/queryCache.ts:151

Returns the existing Query instance for the given options' queryKey/queryHash, or builds and adds a new one to the cache if none exists yet. Used by framework adapters and plugins (e.g. broadcast/persistence) that need to get-or-create a Query directly, bypassing the reactive QueryObserver machinery.

Type Parameters#

TQueryFnData#

TQueryFnData = unknown

TError#

TError = Error

TData#

TData = TQueryFnData

TQueryKey#

TQueryKey extends readonly unknown[] = readonly unknown[]

Parameters#

client#

QueryClient

The client the query belongs to, used to default its options.

options#

WithRequired<QueryOptions<TQueryFnData, TError, TData, TQueryKey, never>, "queryKey">

The query options, including the queryKey. A new query is created with the options defaulted by QueryClient#defaultQueryOptions.

state?#

QueryState<TData, TError>

The initial state of a newly created query, e.g. when hydrating. Ignored if the query already exists.

Returns#

Query<TQueryFnData, TError, TData, TQueryKey>

The existing or newly created query.

Example#

const queryCache = queryClient.getQueryCache()

const query = queryCache.build(queryClient, {
  queryKey: ['posts'],
  queryFn: fetchPosts,
})

clear()#

clear(): void;

Defined in: packages/query-core/src/queryCache.ts:236

Removes all queries from the cache.

Returns#

void

Example#

const queryCache = queryClient.getQueryCache()

queryCache.clear()

find()#

find<TQueryFnData, TError, TData>(filters: WithRequired<QueryFilters<readonly unknown[]>, "queryKey">): 
  | Query<TQueryFnData, TError, TData, readonly unknown[]>
  | undefined;

Defined in: packages/query-core/src/queryCache.ts:305

A slightly more advanced method that can be used to get an existing query instance from the cache. This instance not only contains all the state for the query, but all of the instances, and underlying guts of the query as well. If the query does not exist, undefined is returned.

This is not typically needed for most applications, but can come in handy when needing more information about a query in rare scenarios (e.g. looking at query.state.dataUpdatedAt to decide whether a query is fresh enough to be used as an initial value).

Type Parameters#

TQueryFnData#

TQueryFnData = unknown

TError#

TError = Error

TData#

TData = TQueryFnData

Parameters#

filters#

WithRequired<QueryFilters<readonly unknown[]>, "queryKey">

The filters to match, including the required queryKey. exact defaults to true.

Returns#

| Query<TQueryFnData, TError, TData, readonly unknown[]> | undefined

The first matching query, or undefined.

See#

QueryCache#findAll

Example#

const queryCache = queryClient.getQueryCache()

const query = queryCache.find({ queryKey: ['posts'] })

findAll()#

findAll(filters: QueryFilters<any>): Query<unknown, Error, unknown, readonly unknown[]>[];

Defined in: packages/query-core/src/queryCache.ts:331

An even more advanced method that can be used to get existing query instances from the cache that partially match a query key. If no queries match, an empty array is returned.

This is not typically needed for most applications, but can come in handy when needing more information about queries in rare scenarios.

Parameters#

filters#

QueryFilters<any> = {}

The filters to match. Without filters, every query is returned.

Returns#

Query<unknown, Error, unknown, readonly unknown[]>[]

The matching queries.

See#

QueryCache#find

Example#

const queryCache = queryClient.getQueryCache()

const queries = queryCache.findAll({ queryKey: ['posts'] })

get()#

get<TQueryFnData, TError, TData, TQueryKey>(queryHash: string): 
  | Query<TQueryFnData, TError, TData, TQueryKey>
  | undefined;

Defined in: packages/query-core/src/queryCache.ts:259

Returns the Query instance stored under the given queryHash, or undefined if none exists. Unlike QueryCache#find, this looks up by the already-computed hash rather than by QueryFilters. Used by plugins (e.g. broadcast/hydration) that already have a hash to look up directly.

Type Parameters#

TQueryFnData#

TQueryFnData = unknown

TError#

TError = Error

TData#

TData = TQueryFnData

TQueryKey#

TQueryKey extends readonly unknown[] = readonly unknown[]

Parameters#

queryHash#

string

The hash of the query to look up.

Returns#

| Query<TQueryFnData, TError, TData, TQueryKey> | undefined

The query stored under the hash, or undefined.

Example#

const queryCache = queryClient.getQueryCache()
const queryHash = hashKey(['posts'])

const query = queryCache.get(queryHash)

getAll()#

getAll(): Query<unknown, Error, unknown, readonly unknown[]>[];

Defined in: packages/query-core/src/queryCache.ts:281

Returns all queries within the cache.

Returns#

Query<unknown, Error, unknown, readonly unknown[]>[]

Every query in the cache.

Example#

const queryCache = queryClient.getQueryCache()

const queries = queryCache.getAll()

hasListeners()#

hasListeners(): boolean;

Defined in: packages/query-core/src/subscribable.ts:43

Returns true while at least one listener is registered, false once they have all unsubscribed.

Returns#

boolean

true if at least one listener is registered.

Inherited from#

Subscribable.hasListeners

remove()#

remove(query: Query<any, any, any, any>): void;

Defined in: packages/query-core/src/queryCache.ts:217

Destroys the given Query and removes it from the cache, notifying subscribers with a 'removed' event. A no-op if the query is no longer the one currently stored under its hash (e.g. it was already replaced). Used by plugins (e.g. the broadcast client) that mirror removals across QueryCache instances.

Parameters#

query#

Query<any, any, any, any>

The query to remove.

Returns#

void

Example#

const queryCache = queryClient.getQueryCache()
const query = queryCache.find({ queryKey: ['posts'] })

if (query) {
  queryCache.remove(query)
}

subscribe()#

subscribe(listener: QueryCacheListener): () => void;

Defined in: packages/query-core/src/subscribable.ts:28

Registers a listener to be called on every update this object notifies about. Returns a function that removes the listener again — call it to stop listening. The base class never drops a listener on its own, though some subclasses clear all of theirs in destroy().

Parameters#

listener#

QueryCacheListener

Called on each update, with whatever the subclass passes to its subscribers.

Returns#

A function that removes the listener.

(): void;

Returns#

void

Example#

const unsubscribe = subscribable.subscribe(() => {
  // react to the update
})

unsubscribe()

Inherited from#

Subscribable.subscribe