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---
id: queries
title: Queries
ref: docs/framework/react/guides/queries.md
replace:
{
'React': 'Angular',
'react-query': 'angular-query',
'promise': 'promise or observable',
'custom hooks': 'services',
'the `useQuery` hook': '`injectQuery`',
'`useQuery`': '`injectQuery`',
"TypeScript will also narrow the type of data correctly if you've checked for pending and error before accessing it.": 'TypeScript will only narrow the type when checking boolean signals such as `isPending` and `isError`.',
}
---
[//]: # 'Example'
```ts
import { injectQuery } from '@tanstack/angular-query-experimental'
export class TodosComponent {
info = injectQuery(() => ({ queryKey: ['todos'], queryFn: fetchTodoList }))
}
```
[//]: # 'Example'
[//]: # 'Example2'
```ts
result = injectQuery(() => ({ queryKey: ['todos'], queryFn: fetchTodoList }))
```
[//]: # 'Example2'
[//]: # 'Example3'
```angular-ts
@Component({
selector: 'todos',
standalone: true,
template: `
@if (todos.isPending()) {
<span>Loading...</span>
} @else if (todos.isError()) {
<span>Error: {{ todos.error()?.message }}</span>
} @else {
<!-- We can assume by this point that status === 'success' -->
@for (todo of todos.data(); track todo.id) {
<li>{{ todo.title }}</li>
} @empty {
<li>No todos found</li>
}
}
`,
})
export class PostsComponent {
todos = injectQuery(() => ({
queryKey: ['todos'],
queryFn: fetchTodoList,
}))
}
```
[//]: # 'Example3'
If booleans aren't your thing, you can always use the `status` state as well:
[//]: # 'Example4'
```angular-ts
@Component({
selector: 'todos',
standalone: true,
template: `
@switch (todos.status()) {
@case ('pending') {
<span>Loading...</span>
}
@case ('error') {
<span>Error: {{ todos.error()?.message }}</span>
}
<!-- also status === 'success', but "else" logic works, too -->
@default {
<ul>
@for (todo of todos.data(); track todo.id) {
<li>{{ todo.title }}</li>
} @empty {
<li>No todos found</li>
}
</ul>
}
}
`,
})
class TodosComponent {}
```
[//]: # 'Example4'
[//]: # 'Materials'
[//]: # 'Materials'
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