kysely
Version:
Type safe SQL query builder
209 lines (208 loc) • 6.7 kB
JavaScript
"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.jsonArrayFrom = jsonArrayFrom;
exports.jsonObjectFrom = jsonObjectFrom;
exports.jsonBuildObject = jsonBuildObject;
exports.mergeAction = mergeAction;
const sql_js_1 = require("../raw-builder/sql.js");
/**
* A postgres helper for aggregating a subquery (or other expression) into a JSONB array.
*
* ### Examples
*
* <!-- siteExample("select", "Nested array", 110) -->
*
* While kysely is not an ORM and it doesn't have the concept of relations, we do provide
* helpers for fetching nested objects and arrays in a single query. In this example we
* use the `jsonArrayFrom` helper to fetch person's pets along with the person's id.
*
* Please keep in mind that the helpers under the `kysely/helpers` folder, including
* `jsonArrayFrom`, are not guaranteed to work with third party dialects. In order for
* them to work, the dialect must automatically parse the `json` data type into
* JavaScript JSON values like objects and arrays. Some dialects might simply return
* the data as a JSON string. In these cases you can use the built in `ParseJSONResultsPlugin`
* to parse the results.
*
* ```ts
* import { jsonArrayFrom } from 'kysely/helpers/postgres'
*
* const result = await db
* .selectFrom('person')
* .select((eb) => [
* 'id',
* jsonArrayFrom(
* eb.selectFrom('pet')
* .select(['pet.id as pet_id', 'pet.name'])
* .whereRef('pet.owner_id', '=', 'person.id')
* .orderBy('pet.name')
* ).as('pets')
* ])
* .execute()
* ```
*
* The generated SQL (PostgreSQL):
*
* ```sql
* select "id", (
* select coalesce(json_agg(agg), '[]') from (
* select "pet"."id" as "pet_id", "pet"."name"
* from "pet"
* where "pet"."owner_id" = "person"."id"
* order by "pet"."name"
* ) as agg
* ) as "pets"
* from "person"
* ```
*/
function jsonArrayFrom(expr) {
return (0, sql_js_1.sql) `(select coalesce(json_agg(agg), '[]') from ${expr} as agg)`;
}
/**
* A postgres helper for turning a subquery (or other expression) into a JSON object.
*
* The subquery must only return one row.
*
* ### Examples
*
* <!-- siteExample("select", "Nested object", 120) -->
*
* While kysely is not an ORM and it doesn't have the concept of relations, we do provide
* helpers for fetching nested objects and arrays in a single query. In this example we
* use the `jsonObjectFrom` helper to fetch person's favorite pet along with the person's id.
*
* Please keep in mind that the helpers under the `kysely/helpers` folder, including
* `jsonObjectFrom`, are not guaranteed to work with third-party dialects. In order for
* them to work, the dialect must automatically parse the `json` data type into
* JavaScript JSON values like objects and arrays. Some dialects might simply return
* the data as a JSON string. In these cases you can use the built in `ParseJSONResultsPlugin`
* to parse the results.
*
* ```ts
* import { jsonObjectFrom } from 'kysely/helpers/postgres'
*
* const result = await db
* .selectFrom('person')
* .select((eb) => [
* 'id',
* jsonObjectFrom(
* eb.selectFrom('pet')
* .select(['pet.id as pet_id', 'pet.name'])
* .whereRef('pet.owner_id', '=', 'person.id')
* .where('pet.is_favorite', '=', true)
* ).as('favorite_pet')
* ])
* .execute()
* ```
*
* The generated SQL (PostgreSQL):
*
* ```sql
* select "id", (
* select to_json(obj) from (
* select "pet"."id" as "pet_id", "pet"."name"
* from "pet"
* where "pet"."owner_id" = "person"."id"
* and "pet"."is_favorite" = $1
* ) as obj
* ) as "favorite_pet"
* from "person"
* ```
*/
function jsonObjectFrom(expr) {
return (0, sql_js_1.sql) `(select to_json(obj) from ${expr} as obj)`;
}
/**
* The PostgreSQL `json_build_object` function.
*
* NOTE: This helper is only guaranteed to fully work with the built-in `PostgresDialect`.
* While the produced SQL is compatible with all PostgreSQL databases, some third-party dialects
* may not parse the nested JSON into objects. In these cases you can use the built in
* `ParseJSONResultsPlugin` to parse the results.
*
* ### Examples
*
* ```ts
* import { sql } from 'kysely'
* import { jsonBuildObject } from 'kysely/helpers/postgres'
*
* const result = await db
* .selectFrom('person')
* .select((eb) => [
* 'id',
* jsonBuildObject({
* first: eb.ref('first_name'),
* last: eb.ref('last_name'),
* full: sql<string>`first_name || ' ' || last_name`
* }).as('name')
* ])
* .execute()
*
* result[0]?.id
* result[0]?.name.first
* result[0]?.name.last
* result[0]?.name.full
* ```
*
* The generated SQL (PostgreSQL):
*
* ```sql
* select "id", json_build_object(
* 'first', first_name,
* 'last', last_name,
* 'full', first_name || ' ' || last_name
* ) as "name"
* from "person"
* ```
*/
function jsonBuildObject(obj) {
return (0, sql_js_1.sql) `json_build_object(${sql_js_1.sql.join(Object.keys(obj).flatMap((k) => [sql_js_1.sql.lit(k), obj[k]]))})`;
}
/**
* The PostgreSQL `merge_action` function.
*
* This function can be used in a `returning` clause to get the action that was
* performed in a `mergeInto` query. The function returns one of the following
* strings: `'INSERT'`, `'UPDATE'`, or `'DELETE'`.
*
* ### Examples
*
* ```ts
* import { mergeAction } from 'kysely/helpers/postgres'
*
* const result = await db
* .mergeInto('person as p')
* .using('person_backup as pb', 'p.id', 'pb.id')
* .whenMatched()
* .thenUpdateSet(({ ref }) => ({
* first_name: ref('pb.first_name'),
* updated_at: ref('pb.updated_at').$castTo<string | null>(),
* }))
* .whenNotMatched()
* .thenInsertValues(({ ref}) => ({
* id: ref('pb.id'),
* first_name: ref('pb.first_name'),
* created_at: ref('pb.updated_at'),
* updated_at: ref('pb.updated_at').$castTo<string | null>(),
* }))
* .returning([mergeAction().as('action'), 'p.id', 'p.updated_at'])
* .execute()
*
* result[0].action
* ```
*
* The generated SQL (PostgreSQL):
*
* ```sql
* merge into "person" as "p"
* using "person_backup" as "pb" on "p"."id" = "pb"."id"
* when matched then update set
* "first_name" = "pb"."first_name",
* "updated_at" = "pb"."updated_at"::text
* when not matched then insert values ("id", "first_name", "created_at", "updated_at")
* values ("pb"."id", "pb"."first_name", "pb"."updated_at", "pb"."updated_at")
* returning merge_action() as "action", "p"."id", "p"."updated_at"
* ```
*/
function mergeAction() {
return (0, sql_js_1.sql) `merge_action()`;
}