Generic find query
A generic type-safe helper function for finding a row by a column value:
import type {
ColumnType,
Generated,
GeneratedAlways,
Insertable,
Kysely,
Selectable,
SqlBool,
Updateable,
} from 'kysely'
export interface Database {
audit: AuditTable
person: PersonTable
person_backup: PersonTable
pet: PetTable
toy: ToyTable
wine: WineTable
wine_stock_change: WineStockChangeTable
}
interface AuditTable {
id: Generated<number>
action: string
}
interface PersonTable {
id: Generated<number>
address: { city: string } | null
age: number | null
birthdate: ColumnType<Date | null, string | null | undefined, string | null>
created_at: GeneratedAlways<Date>
deleted_at: ColumnType<Date | null, string | null | undefined, string | null>
experience: { role: string }[] | null
first_name: string
gender: 'male' | 'female' | 'other' | null
has_pets: Generated<'Y' | 'N'>
last_name: string | null
middle_name: string | null
nicknames: string[] | null
nullable_column: string | null
profile: {
addresses: { city: string }[]
website: { url: string }
} | null
updated_at: ColumnType<Date | null, string | null | undefined, string | null>
marital_status: 'single' | 'married' | 'divorced' | 'widowed' | null
}
interface PetTable {
id: Generated<number>
created_at: GeneratedAlways<Date>
is_favorite: Generated<SqlBool>
name: string
owner_id: number
species: Species
}
interface ToyTable {
id: Generated<number>
name: string
pet_id: number
price: number
}
interface WineTable {
id: Generated<number>
name: string
stock: number
}
interface WineStockChangeTable {
id: Generated<number>
stock_delta: number
wine_name: string
}
export type Person = Selectable<PersonTable>
export type NewPerson = Insertable<PersonTable>
export type PersonUpdate = Updateable<PersonTable>
export type Pet = Selectable<PetTable>
export type NewPet = Insertable<PetTable>
export type PetUpdate = Updateable<PetTable>
export type Species = 'dog' | 'cat' | 'hamster'
declare global {
// @ts-ignore
export class Buffer {
static isBuffer(obj: unknown): obj is { length: number }
static compare(a: Buffer, b: Buffer): number
}
export const db: Kysely<Database>
export function functionThatExpectsPersonWithNonNullValue(
person: Person & { nullable_column: string },
): void
}
import { SelectType } from 'kysely'
import { Database } from 'type-editor'
async function getRowByColumn<
T extends keyof Database,
C extends keyof Database[T] & string,
V extends SelectType<Database[T][C]>,
>(t: T, c: C, v: V) {
// We need to use the dynamic module since the table name
// is not known at compile time.
const { table, ref } = db.dynamic
return await db
.selectFrom(table(t).as('t'))
.selectAll()
.where(ref(c), '=', v)
.orderBy('t.id')
.executeTakeFirstOrThrow()
}
const person = await getRowByColumn('person', 'first_name', 'Arnold')
More examples
The API documentation is packed with examples. The API docs are hosted here, but you can access the same documentation by hovering over functions/methods/classes in your IDE. The examples are always just one hover away!
For example, check out these sections: