"Parallel" queries are queries that are executed in parallel, or at the same time so as to maximize fetching concurrency.
When the number of parallel queries does not change, there is no extra effort to use parallel queries. Just use any number of TanStack Query's useQuery and useInfiniteQuery hooks side-by-side!
<script setup lang="ts">
// The following queries will execute in parallel
const usersQuery = useQuery({ queryKey: ['users'], queryFn: fetchUsers })
const teamsQuery = useQuery({ queryKey: ['teams'], queryFn: fetchTeams })
const projectsQuery = useQuery({
queryKey: ['projects'],
queryFn: fetchProjects,
})
</script>
<script setup lang="ts">
// The following queries will execute in parallel
const usersQuery = useQuery({ queryKey: ['users'], queryFn: fetchUsers })
const teamsQuery = useQuery({ queryKey: ['teams'], queryFn: fetchTeams })
const projectsQuery = useQuery({
queryKey: ['projects'],
queryFn: fetchProjects,
})
</script>
If the number of queries you need to execute is changing from render to render, you cannot use manual querying since that would violate the rules of hooks. Instead, TanStack Query provides a useQueries hook, which you can use to dynamically execute as many queries in parallel as you'd like.
useQueries accepts an options object with a queries key whose value is an array of query objects. It returns an array of query results:
const users = computed(...)
const queries = computed(() => users.value.map(user => {
return {
queryKey: ['user', user.id],
queryFn: () => fetchUserById(user.id),
}
})
);
const userQueries = useQueries({queries: queries})
const users = computed(...)
const queries = computed(() => users.value.map(user => {
return {
queryKey: ['user', user.id],
queryFn: () => fetchUserById(user.id),
}
})
);
const userQueries = useQueries({queries: queries})