# GroupKeys

Defined in: [packages/db/src/query/builder/group-keys.ts:9](https://github.com/TanStack/db/blob/main/packages/db/src/query/builder/group-keys.ts#L9)

Group keys for `query.groupBy(...)` when the query has no aggregate.
Aggregates such as `count` bring the grouping compiler themselves.

## Type Parameters

### TContext

`TContext` *extends* [`Context`](Context.md)

## Properties

### callback

```ts
callback: GroupByCallback<TContext>;
```

Defined in: [packages/db/src/query/builder/group-keys.ts:10](https://github.com/TanStack/db/blob/main/packages/db/src/query/builder/group-keys.ts#L10)

***

### grouping

```ts
grouping: object;
```

Defined in: [packages/db/src/query/builder/group-keys.ts:11](https://github.com/TanStack/db/blob/main/packages/db/src/query/builder/group-keys.ts#L11)

#### processGroupBy()

```ts
processGroupBy: (pipeline, groupByClause, valueIdentity, isSourceRef, havingClauses?, selectClause?, fnHavingClauses?, aggregateCollectionId?, mainSource?, sanitizeCallbackRows) => NamespacedAndKeyedStream;
```

Processes the GROUP BY clause with optional HAVING and SELECT
Works with the new $selected structure from early SELECT processing

##### Parameters

###### pipeline

[`NamespacedAndKeyedStream`](../type-aliases/NamespacedAndKeyedStream.md)

###### groupByClause

[`GroupBy`](../@tanstack/namespaces/IR/type-aliases/GroupBy.md)

###### valueIdentity

`ValueIdentity`

###### isSourceRef

(`ref`) => `boolean`

Whether a ref reads a field of the query's own rows.

###### havingClauses?

[`Where`](../@tanstack/namespaces/IR/type-aliases/Where.md)[]

###### selectClause?

[`Select`](../@tanstack/namespaces/IR/type-aliases/Select.md)

###### fnHavingClauses?

(`row`) => `any`[]

###### aggregateCollectionId?

`string`

###### mainSource?

`string`

###### sanitizeCallbackRows?

`boolean` = `false`

##### Returns

[`NamespacedAndKeyedStream`](../type-aliases/NamespacedAndKeyedStream.md)

#### replaceAggregatesByRefs()

```ts
replaceAggregatesByRefs: (havingExpr, selectClause, resultAlias) => BasicExpression;
```

Transforms expressions to replace aggregate functions with references to computed values.

For aggregate expressions, finds matching aggregates in the SELECT clause and replaces them
with PropRef([resultAlias, alias]) to reference the computed aggregate value.

Ref expressions (table columns and $selected fields) and value expressions are passed through unchanged.
Function expressions are recursively transformed.

##### Parameters

###### havingExpr

The expression to transform (can be aggregate, ref, func, or val)

[`Aggregate`](../@tanstack/namespaces/IR/classes/Aggregate.md)\<`any`\> | [`BasicExpression`](../@tanstack/namespaces/IR/type-aliases/BasicExpression.md)

###### selectClause

[`Select`](../@tanstack/namespaces/IR/type-aliases/Select.md)

The SELECT clause containing aliases and aggregate definitions

###### resultAlias

`string` = `...`

The namespace alias for SELECT results (default: '$selected')

##### Returns

[`BasicExpression`](../@tanstack/namespaces/IR/type-aliases/BasicExpression.md)

A transformed BasicExpression that references computed values instead of raw expressions