useQuery

function useQuery<TQueryFnData, TError, TData, TQueryKey>(options: UndefinedInitialDataOptions<TQueryFnData, TError, TData, TQueryKey>, queryClient?: () => QueryClient): UseQueryResult<TData, TError>;
function useQuery<TQueryFnData, TError, TData, TQueryKey>(options: DefinedInitialDataOptions<TQueryFnData, TError, TData, TQueryKey>, queryClient?: () => QueryClient): DefinedUseQueryResult<TData, TError>;

function useQuery<TQueryFnData, TError, TData, TQueryKey>(options: UndefinedInitialDataOptions<TQueryFnData, TError, TData, TQueryKey>, queryClient?: () => QueryClient): UseQueryResult<TData, TError>;

import { For, Match, Switch } from 'solid-js'
import { useQuery } from '@tanstack/solid-query'

function Posts() {
  const postsQuery = useQuery(() => ({
    queryKey: ['posts'],
    queryFn: fetchPosts,
  }))

  return (
    <Switch>
      <Match when={postsQuery.isPending}>Loading...</Match>
      <Match when={postsQuery.isError}>Error: {postsQuery.error.message}</Match>
      <Match when={postsQuery.isSuccess}>
        <ul>
          <For each={postsQuery.data}>{(post) => <li>{post.title}</li>}</For>
        </ul>
        <div>{postsQuery.isFetching ? 'Background Updating...' : ' '}</div>
      </Match>
    </Switch>
  )
}

import { Match, Switch } from 'solid-js'
import { useQuery } from '@tanstack/solid-query'

function PostCount() {
  const postsQuery = useQuery(() => ({
    queryKey: ['posts'],
    queryFn: fetchPosts,
    select: (posts) => posts.length,
  }))

  return (
    <Switch>
      <Match when={postsQuery.isPending}>Loading...</Match>
      <Match when={postsQuery.isError}>Error: {postsQuery.error.message}</Match>
      <Match when={postsQuery.isSuccess}>{postsQuery.data} posts</Match>
    </Switch>
  )
}

import { Match, Switch } from 'solid-js'
import { useQuery } from '@tanstack/solid-query'

function Post(props: { postId: number | undefined }) {
  const postQuery = useQuery(() => ({
    queryKey: ['post', props.postId],
    queryFn: () => fetchPost(props.postId!),
    enabled: props.postId != null,
  }))

  return (
    <Switch fallback={<h1>{postQuery.data?.title}</h1>}>
      <Match when={props.postId == null}>Select a post</Match>
      <Match when={postQuery.isLoading}>Loading...</Match>
      <Match when={postQuery.isError}>Error: {postQuery.error.message}</Match>
    </Switch>
  )
}

import { Match, Switch } from 'solid-js'
import { skipToken, useQuery } from '@tanstack/solid-query'

function Post(props: { postId: number | undefined }) {
  const postQuery = useQuery(() => ({
    queryKey: ['post', props.postId],
    queryFn: props.postId != null ? () => fetchPost(props.postId!) : skipToken,
  }))

  return (
    <Switch fallback={<h1>{postQuery.data?.title}</h1>}>
      <Match when={props.postId == null}>Select a post</Match>
      <Match when={postQuery.isLoading}>Loading...</Match>
      <Match when={postQuery.isError}>Error: {postQuery.error.message}</Match>
    </Switch>
  )
}

import { useQuery, useQueryClient } from '@tanstack/solid-query'

function Post(props: { postId: number }) {
  const queryClient = useQueryClient()

  const postQuery = useQuery(() => ({
    queryKey: ['post', props.postId],
    queryFn: () => fetchPost(props.postId),
    initialData: () =>
      queryClient
        .getQueryData<Array<Post>>(['posts'])
        ?.find((post) => post.id === props.postId),
    initialDataUpdatedAt: () =>
      queryClient.getQueryState(['posts'])?.dataUpdatedAt,
  }))

  return postQuery.isError ? <span>Error: {postQuery.error.message}</span> : <h1>{postQuery.data?.title}</h1>
}

import { For, createSignal } from 'solid-js'
import { keepPreviousData, useQuery } from '@tanstack/solid-query'

function Posts() {
  const [page, setPage] = createSignal(0)

  const postsQuery = useQuery(() => ({
    queryKey: ['posts', page()],
    queryFn: () => fetchPosts(page()),
    placeholderData: keepPreviousData,
  }))

  return (
    <div>
      <ul>
        <For each={postsQuery.data}>{(post) => <li>{post.title}</li>}</For>
      </ul>
      <button
        disabled={postsQuery.isPlaceholderData}
        onClick={() => setPage((old) => old + 1)}
      >
        Next Page
      </button>
    </div>
  )
}

function useQuery<TQueryFnData, TError, TData, TQueryKey>(options: DefinedInitialDataOptions<TQueryFnData, TError, TData, TQueryKey>, queryClient?: () => QueryClient): DefinedUseQueryResult<TData, TError>;

import { For } from 'solid-js'
import { useQuery } from '@tanstack/solid-query'

function Posts() {
  // `postsQuery.data` is never `undefined`, thanks to `initialData` — even if a refetch fails, so the
  // list stays visible alongside the error.
  const postsQuery = useQuery(() => ({
    queryKey: ['posts'],
    queryFn: fetchPosts,
    initialData: [],
  }))

  return (
    <div>
      {postsQuery.isError ? <span>Error: {postsQuery.error.message}</span> : null}
      <ul>
        <For each={postsQuery.data}>{(post) => <li>{post.title}</li>}</For>
      </ul>
    </div>
  )
}