--- id: useQuery title: useQuery --- ```js const { data, dataUpdatedAt, error, errorUpdatedAt, failureCount, isError, isFetched, isFetchedAfterMount, isFetching, isIdle, isLoading, isLoadingError, isPlaceholderData, isPreviousData, isRefetchError, isRefetching, isStale, isSuccess, refetch, remove, status, } = useQuery(queryKey, queryFn?, { cacheTime, enabled, initialData, initialDataUpdatedAt isDataEqual, keepPreviousData, meta, notifyOnChangeProps, notifyOnChangePropsExclusions, onError, onSettled, onSuccess, placeholderData, queryKeyHashFn, refetchInterval, refetchIntervalInBackground, refetchOnMount, refetchOnReconnect, refetchOnWindowFocus, retry, retryOnMount, retryDelay, select, staleTime, structuralSharing, suspense, useErrorBoundary, }) // or using the object syntax const result = useQuery({ queryKey, queryFn, enabled, }) ``` **Options** - `queryKey: string | unknown[]` - **Required** - The query key to use for this query. - The query key will be hashed into a stable hash. See [Query Keys](../guides/query-keys) for more information. - The query will automatically update when this key changes (as long as `enabled` is not set to `false`). - `queryFn: (context: QueryFunctionContext) => Promise` - **Required, but only if no default query function has been defined** See [Default Query Function](../guides/default-query-function) for more information. - The function that the query will use to request data. - Receives a `QueryFunctionContext` object with the following variables: - `queryKey: EnsuredQueryKey`: the queryKey, guaranteed to be an Array - Must return a promise that will either resolve data or throw an error. - `enabled: boolean` - Set this to `false` to disable this query from automatically running. - Can be used for [Dependent Queries](../guides/dependent-queries). - `retry: boolean | number | (failureCount: number, error: TError) => boolean` - If `false`, failed queries will not retry by default. - If `true`, failed queries will retry infinitely. - If set to a `number`, e.g. `3`, failed queries will retry until the failed query count meets that number. - `retryOnMount: boolean` - If set to `false`, the query will not be retried on mount if it contains an error. Defaults to `true`. - `retryDelay: number | (retryAttempt: number, error: TError) => number` - This function receives a `retryAttempt` integer and the actual Error and returns the delay to apply before the next attempt in milliseconds. - A function like `attempt => Math.min(attempt > 1 ? 2 ** attempt * 1000 : 1000, 30 * 1000)` applies exponential backoff. - A function like `attempt => attempt * 1000` applies linear backoff. - `staleTime: number | Infinity` - Optional - Defaults to `0` - The time in milliseconds after data is considered stale. This value only applies to the hook it is defined on. - If set to `Infinity`, the data will never be considered stale - `cacheTime: number | Infinity` - Defaults to `5 * 60 * 1000` (5 minutes) - The time in milliseconds that unused/inactive cache data remains in memory. When a query's cache becomes unused or inactive, that cache data will be garbage collected after this duration. When different cache times are specified, the longest one will be used. - If set to `Infinity`, will disable garbage collection - `queryKeyHashFn: (queryKey: QueryKey) => string` - Optional - If specified, this function is used to hash the `queryKey` to a string. - `refetchInterval: number | false | ((data: TData | undefined, query: Query) => number | false)` - Optional - If set to a number, all queries will continuously refetch at this frequency in milliseconds - If set to a function, the function will be executed with the latest data and query to compute a frequency - `refetchIntervalInBackground: boolean` - Optional - If set to `true`, queries that are set to continuously refetch with a `refetchInterval` will continue to refetch while their tab/window is in the background - `refetchOnMount: boolean | "always" | ((query: Query) => boolean | "always")` - Optional - Defaults to `true` - If set to `true`, the query will refetch on mount if the data is stale. - If set to `false`, the query will not refetch on mount. - If set to `"always"`, the query will always refetch on mount. - If set to a function, the function will be executed with the query to compute the value - `refetchOnWindowFocus: boolean | "always" | ((query: Query) => boolean | "always")` - Optional - Defaults to `true` - If set to `true`, the query will refetch on window focus if the data is stale. - If set to `false`, the query will not refetch on window focus. - If set to `"always"`, the query will always refetch on window focus. - If set to a function, the function will be executed with the query to compute the value - `refetchOnReconnect: boolean | "always" | ((query: Query) => boolean | "always")` - Optional - Defaults to `true` - If set to `true`, the query will refetch on reconnect if the data is stale. - If set to `false`, the query will not refetch on reconnect. - If set to `"always"`, the query will always refetch on reconnect. - If set to a function, the function will be executed with the query to compute the value - `notifyOnChangeProps: string[] | "tracked"` - Optional - If set, the component will only re-render if any of the listed properties change. - If set to `['data', 'error']` for example, the component will only re-render when the `data` or `error` properties change. - If set to `"tracked"`, access to properties will be tracked, and the component will only re-render when one of the tracked properties change. - `notifyOnChangePropsExclusions: string[]` - Optional - If set, the component will not re-render if any of the listed properties change. - If set to `['isStale']` for example, the component will not re-render when the `isStale` property changes. - `onSuccess: (data: TData) => void` - Optional - This function will fire any time the query successfully fetches new data or the cache is updated via `setQueryData`. - `onError: (error: TError) => void` - Optional - This function will fire if the query encounters an error and will be passed the error. - `onSettled: (data?: TData, error?: TError) => void` - Optional - This function will fire any time the query is either successfully fetched or errors and be passed either the data or error - `select: (data: TData) => unknown` - Optional - This option can be used to transform or select a part of the data returned by the query function. - `suspense: boolean` - Optional - Set this to `true` to enable suspense mode. - When `true`, `useQuery` will suspend when `status === 'loading'` - When `true`, `useQuery` will throw runtime errors when `status === 'error'` - `initialData: TData | () => TData` - Optional - If set, this value will be used as the initial data for the query cache (as long as the query hasn't been created or cached yet) - If set to a function, the function will be called **once** during the shared/root query initialization, and be expected to synchronously return the initialData - Initial data is considered stale by default unless a `staleTime` has been set. - `initialData` **is persisted** to the cache - `initialDataUpdatedAt: number | (() => number | undefined)` - Optional - If set, this value will be used as the time (in milliseconds) of when the `initialData` itself was last updated. - `placeholderData: TData | () => TData` - Optional - If set, this value will be used as the placeholder data for this particular query observer while the query is still in the `loading` data and no initialData has been provided. - `placeholderData` is **not persisted** to the cache - `keepPreviousData: boolean` - Optional - Defaults to `false` - If set, any previous `data` will be kept when fetching new data because the query key changed. - `structuralSharing: boolean` - Optional - Defaults to `true` - If set to `false`, structural sharing between query results will be disabled. - `useErrorBoundary: undefined | boolean | (error: TError, query: Query) => boolean` - Defaults to the global query config's `useErrorBoundary` value, which is `undefined` - Set this to `true` if you want errors to be thrown in the render phase and propagate to the nearest error boundary - Set this to `false` to disable `suspense`'s default behavior of throwing errors to the error boundary. - If set to a function, it will be passed the error and the query, and it should return a boolean indicating whether to show the error in an error boundary (`true`) or return the error as state (`false`) - `meta: Record` - Optional - If set, stores additional information on the query cache entry that can be used as needed. It will be accessible wherever the `query` is available, and is also part of the `QueryFunctionContext` provided to the `queryFn`. **Returns** - `status: String` - Will be: - `idle` if the query is idle. This only happens if a query is initialized with `enabled: false` and no initial data is available. - `loading` if the query is in a "hard" loading state. This means there is no cached data and the query is currently fetching, eg `isFetching === true` - `error` if the query attempt resulted in an error. The corresponding `error` property has the error received from the attempted fetch - `success` if the query has received a response with no errors and is ready to display its data. The corresponding `data` property on the query is the data received from the successful fetch or if the query's `enabled` property is set to `false` and has not been fetched yet `data` is the first `initialData` supplied to the query on initialization. - `isIdle: boolean` - A derived boolean from the `status` variable above, provided for convenience. - `isLoading: boolean` - A derived boolean from the `status` variable above, provided for convenience. - `isSuccess: boolean` - A derived boolean from the `status` variable above, provided for convenience. - `isError: boolean` - A derived boolean from the `status` variable above, provided for convenience. - `isLoadingError: boolean` - Will be `true` if the query failed while fetching for the first time. - `isRefetchError: boolean` - Will be `true` if the query failed while refetching. - `data: TData` - Defaults to `undefined`. - The last successfully resolved data for the query. - `dataUpdatedAt: number` - The timestamp for when the query most recently returned the `status` as `"success"`. - `error: null | TError` - Defaults to `null` - The error object for the query, if an error was thrown. - `errorUpdatedAt: number` - The timestamp for when the query most recently returned the `status` as `"error"`. - `isStale: boolean` - Will be `true` if the data in the cache is invalidated or if the data is older than the given `staleTime`. - `isPlaceholderData: boolean` - Will be `true` if the data shown is the placeholder data. - `isPreviousData: boolean` - Will be `true` when `keepPreviousData` is set and data from the previous query is returned. - `isFetched: boolean` - Will be `true` if the query has been fetched. - `isFetchedAfterMount: boolean` - Will be `true` if the query has been fetched after the component mounted. - This property can be used to not show any previously cached data. - `isFetching: boolean` - Is `true` whenever a request is in-flight, which includes initial `loading` as well as background refetches. - Will be `true` if the query is currently fetching, including background fetching. - `isRefetching: boolean` - Is `true` whenever a background refetch is in-flight, which _does not_ include initial `loading` - Is the same as `isFetching && !isLoading` - `failureCount: number` - The failure count for the query. - Incremented every time the query fails. - Reset to `0` when the query succeeds. - `errorUpdateCount: number` - The sum of all errors. - `refetch: (options: { throwOnError: boolean, cancelRefetch: boolean }) => Promise` - A function to manually refetch the query. - If the query errors, the error will only be logged. If you want an error to be thrown, pass the `throwOnError: true` option - If `cancelRefetch` is `true`, then the current request will be cancelled before a new request is made - `remove: () => void` - A function to remove the query from the cache.