kysely
Version:
Type safe SQL query builder
49 lines (48 loc) • 1.63 kB
TypeScript
import { DeleteResult } from '../query-builder/delete-result.js';
import { InsertResult } from '../query-builder/insert-result.js';
import { MergeResult } from '../query-builder/merge-result.js';
import { UpdateResult } from '../query-builder/update-result.js';
import { CompiledQuery } from '../query-compiler/compiled-query.js';
import { Compilable } from './compilable.js';
import { Simplify } from './type-utils.js';
/**
* A helper type that allows inferring a select/insert/update/delete query's result
* type from a query builder or compiled query.
*
* ### Examples
*
* Infer a query builder's result type:
*
* ```ts
* import { InferResult } from 'kysely'
*
* const query = db
* .selectFrom('person')
* .innerJoin('pet', 'pet.owner_id', 'person.id')
* .select(['person.first_name', 'pet.name'])
*
* type QueryResult = InferResult<typeof query> // { first_name: string; name: string; }[]
* ```
*
* Infer a compiled query's result type:
*
* ```ts
* import { InferResult } from 'kysely'
*
* const compiledQuery = db
* .insertInto('person')
* .values({
* first_name: 'Foo',
* last_name: 'Barson',
* gender: 'other',
* age: 15,
* })
* .returningAll()
* .compile()
*
* type QueryResult = InferResult<typeof compiledQuery> // Selectable<Person>[]
* ```
*/
export type InferResult<C extends Compilable<any> | CompiledQuery<any>> = C extends Compilable<infer O> ? ResolveResult<O> : C extends CompiledQuery<infer O> ? ResolveResult<O> : never;
type ResolveResult<O> = O extends InsertResult | UpdateResult | DeleteResult | MergeResult ? O : Simplify<O>[];
export {};