Class DuckDbDialect

config: {
    database: Database | (() => Promise<Database>);
    onCreateConnection?: ((conection) => Promise<void>);
    tableMappings: {
        [tableName: string]: string;
    };
}

• database: Database | (() => Promise<Database>)

  duckdb.Database instance or a function returns a Promise of duckdb.Database instance.

• Optional onCreateConnection?: ((conection) => Promise<void>)

  • • (conection): Promise<void>

    • called when a connection is created.

      Parameters

      • conection: Connection

        duckdb.Connection instance that is created.

      Returns Promise<void>

      Promise

• tableMappings: {
      [tableName: string]: string;
  }

  Mappings of table name in kysely to duckdb table expressions.

  Duckdb can read external source(file, url or database) as table like: SELECT * FROM read_json_objects('path/to/file/*.json'). You can use raw duckdb table expression as table name, but it may be too long, preserving too many implementation details.

  This mappings is used to replace table name string to duckdb table expression.

  Example

  const dialect = new DuckDbDialect({
   database: db,
   tableMappings: {
     person: 'read_json_object("s3://my-bucket/person.json?s3_access_key_id=key&s3_secret_access_key=secret")'
   }
  });
  
  const db = new Kysely<{
    person: { first_name: string, last_name: string }, // 'person' is defined in tableMappings
    pet: { name: string, species: 'cat' | 'dog' },     // 'pet' is *not* defined in tableMappings
  >({ dialect });
  
  await db.selectFrom("person").selectAll().execute();
  // => Executed query is: `SELECT * FROM read_json_object("s3://my-bucket/person.json?s3_access_key_id=key&s3_secret_access_key=secret");`
  Copy

  await db.selectFrom("pet").selectAll().execute(); // => Executed query is: SELECT * FROM pet;

  • [tableName: string]: string

db: Kysely<any>