Kysely Dialect for DuckDB Wasm

This dialect allows you to use Kysely with DuckDB Wasm.

This is forked from kysely-duckdb.

Installation

npm install --save kysely @duckdb/duckdb-wasm @coji/kysely-duckdb-wasm

Usage

import * as duckdb from '@duckdb/duckdb-wasm'
import duckdbWorker from '@duckdb/duckdb-wasm/dist/duckdb-browser-eh.worker.js?worker'
import duckdbWasm from '@duckdb/duckdb-wasm/dist/duckdb-eh.wasm?url'
import { Kysely } from "kysely";
import { DuckDbDialect } from "@coji/kysely-duckdb-wasm";

const logger = new duckdb.ConsoleLogger(duckdb.LogLevel.ERROR)
const worker = new duckdbWorker()
db = new duckdb.AsyncDuckDB(logger, worker)
await db.instantiate(duckdbWasm)
const duckdbDialect = new DuckDbDialect({
  database: wasmdb,
  tableMappings: {},
})
const kysely = new Kysely<DatabaseSchema>({ dialect: duckdbDialect });
const res = await kysely.selectFrom("person").selectAll().execute();

Configrations

The configuration object of DuckDbDialect can contain the following properties:

• tableMappings: A mapping of table names in Kysely to DuckDB table expressions. This is useful if you want to use DuckDB's external data sources, such as JSON files or CSV files.

DuckDB DataTypes Supports (Experimental Feature)

DuckDB supports various data types like arrays, structs, blobs and more. Kysely has not built in supports for these types, but it can handle almost of these using raw SQL feature.

This package includes some shallow helper for these types.

import type { DuckDBNodeDataTypes } from "kysely-duckdb";
import { datatypes } from "kysely-dockdb";

// DuckDBNodeDataTypes: type mappings for table schema
export interface Database {
  t1: {
    int_list: number[];
    string_list: string[];
    map1: DuckDBNodeDataTypes["MAP"]; // `map` is alias of string now. The returned value from duckdb is like '{a=1,b=2}'
    struct1: {
      x: number;
      y: string;
    };
    bitstring1: DuckDBNodeDataTypes["BIT"];
    blob1: DuckDBNodeDataTypes["BLOB"];
    bool1: DuckDBNodeDataTypes["BOOLEAN"];
    date1: DuckDBNodeDataTypes["DATE"];
    timestamp1: DuckDBNodeDataTypes["TIMESTAMP"];
    timestamptz1: DuckDBNodeDataTypes["TIMESTAMPTZ"];
    interval1: DuckDBNodeDataTypes["INTERVAL"];
  };
}

...

// datatypes: type constructors
const kysely = new Kysely<Database>({dialect: duckDbDialect});
await kysely
  .insertInto("t1")
  .values([{
    int_list: datatypes.list([3, 4, 5]),
    string_list: datatypes.list(["d", "e", "f"]),
    map1: types.map([[1, 2], [3, 4]]),
    struct1: datatypes.struct({
      x: sql`${1}`,
      y: sql`${"aaa"}`,
    }),
    bitstring1: datatypes.bit("010101"),
    blob1: datatypes.blob(Buffer.from([0xBB, 0xCC])),
    bool1: true,
    date1: datatypes.date(new Date()),
    timestamp1: datatypes.timestamp(new Date()),
    timestamptz1: datatypes.timestamptz(new Date().toISOString().slice(0, -1) + "+03:00"),
    interval1: sql`INTERVAL 1 YEAR`,
  }])
  .execute();