Type Alias: ResultTypeFromSelect<TSelectObject>

type ResultTypeFromSelect<TSelectObject> = IsAny<TSelectObject> extends true ? any : WithoutRefBrand<Prettify<{ [K in keyof TSelectObject]: NeedsExtraction<TSelectObject[K]> extends true ? ExtractExpressionType<TSelectObject[K]> : TSelectObject[K] extends ToArrayWrapper<infer T> ? T[] : TSelectObject[K] extends ConcatToArrayWrapper<any> ? string : TSelectObject[K] extends MaterializeWrapper<infer T, infer IsSingle> ? IsSingle extends true ? T | undefined : T[] : TSelectObject[K] extends { __brand: "CaseWhenWrapper"; _result?: infer T } ? ResultTypeFromCaseWhen<T> : (...)[(...)] extends QueryBuilder<(...)> ? Collection<(...)> : (...) extends (...) ? (...) : (...) }>>;

type ResultTypeFromSelect<TSelectObject> = IsAny<TSelectObject> extends true ? any : WithoutRefBrand<Prettify<{ [K in keyof TSelectObject]: NeedsExtraction<TSelectObject[K]> extends true ? ExtractExpressionType<TSelectObject[K]> : TSelectObject[K] extends ToArrayWrapper<infer T> ? T[] : TSelectObject[K] extends ConcatToArrayWrapper<any> ? string : TSelectObject[K] extends MaterializeWrapper<infer T, infer IsSingle> ? IsSingle extends true ? T | undefined : T[] : TSelectObject[K] extends { __brand: "CaseWhenWrapper"; _result?: infer T } ? ResultTypeFromCaseWhen<T> : (...)[(...)] extends QueryBuilder<(...)> ? Collection<(...)> : (...) extends (...) ? (...) : (...) }>>;

Defined in: packages/db/src/query/builder/types.ts:389

ResultTypeFromSelect - Infers the result type from a select object

This complex type transforms the input to select() into the actual TypeScript type that the query will return. It handles all the different kinds of values that can appear in a select clause:

Ref/RefProxy Extraction:

RefProxy<T> → T: Extracts the underlying type
Ref<T> | undefined → T | undefined: Preserves optionality
Ref<T> | null → T | null: Preserves nullability

Expression Types:

BasicExpression<T> → T: Function results like upper() → string
Aggregate<T> → T: Aggregation results like count() → number

JavaScript Literals (pass through as-is):

string → string: String literals remain strings
number → number: Numeric literals remain numbers
boolean → boolean: Boolean literals remain booleans
null → null: Explicit null remains null
undefined → undefined: Direct undefined values

Nested Objects (recursive):

Plain objects are recursively processed to handle nested projections
RefProxy objects are detected and their types extracted

Example transformation:

typescript

// Input:
{ id: Ref<number>, name: Ref<string>, status: 'active', count: 42, profile: { bio: Ref<string> } }

// Output:
{ id: number, name: string, status: 'active', count: 42, profile: { bio: string } }

// Input:
{ id: Ref<number>, name: Ref<string>, status: 'active', count: 42, profile: { bio: Ref<string> } }

// Output:
{ id: number, name: string, status: 'active', count: 42, profile: { bio: string } }

ResultTypeFromSelect

Type Alias: ResultTypeFromSelect<TSelectObject>#

Type Parameters#

TSelectObject#

Type Alias: ResultTypeFromSelect<TSelectObject>

Type Parameters

TSelectObject