# collectCollectionSources

# Function: collectCollectionSources()

```ts
function collectCollectionSources(query): CollectionRef[];
```

Defined in: [packages/db/src/query/ir.ts:266](https://github.com/TanStack/db/blob/main/packages/db/src/query/ir.ts#L266)

Returns each lexical Collection source in a query tree once.

## Parameters

### query

[`QueryIR`](../interfaces/QueryIR.md)

## Returns

[`CollectionRef`](../classes/CollectionRef.md)[]