/**
 * SPDX-PackageName: kwaeri/postgresql-database-driver
 * SPDX-PackageVersion: 0.5.0
 * SPDX-FileCopyrightText: © 2014 - 2022 Richard Winters <kirvedx@gmail.com> and contributors
 * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception OR MIT
 */
import Postgres from 'pg';
import { DatabaseDriver, DriverConnectionBits, QueryResult } from '@kwaeri/database-driver';
/**
 * The PostgreSQLDriver implements the PostgreSQL database provider
 */
export declare class PostgreSQLDriver extends DatabaseDriver {
    /**
     * @var { Postgres./Pool } pool
     */
    pool: Postgres.Pool;
    /**
     * Class constructor
     */
    constructor(config: DriverConnectionBits);
    /**
     * Executes a transaction [checkout, use, return] query on a pooled client, using the postgres
     * database driver.
     *
     * @param { string } query The query string to be executed, with optional placeholders (i.e. $1, $2, $3 ... )
     * @param { any[] } bits An array of parameter placeholders (i.e. [1, "Richard"].)
     *
     * @return { Promise<QueryResult> } A promise for a {@link QueryResult} object.
     *
     * **Example**:
     *
     * ```typescript
     * const { rows, fields } = await query( 'select * from people where first_name=$1;', ["Richard"]);
     * ```
     *
     * Though, if you're not using parameters, the bits argument is entirely optional and can be left out.
     *
     * See the [official documentation](https://node-postgres.com/features/pooling)
     */
    clientQuery<T extends QueryResult>(query: string, bits?: any[]): Promise<T>;
    /**
     * Executes a standard [the preferred way to] query on any available client in the pool, using the postgres
     * database driver.
     *
     * @param { string } query The query string to be executed, with optional placeholders (i.e. $1, $2, $3 ... )
     * @param { any[] } bits An array of parameter placeholders (i.e. [1, "Richard"].)
     *
     * @return { Promise<QueryResult> } A promise for a {@link QueryResult} object.
     *
     * **Example**:
     *
     * ```typescript
     * const { rows, fields } = await query( 'select * from people where first_name=$1;', ["Richard"]);
     * ```
     *
     * Though, if you're not using parameters, the bits argument is entirely optional and can be left out.
     *
     * See the [official documentation](https://node-postgres.com/features/pooling)
     */
    query<T extends QueryResult>(query: string, bits?: any[]): Promise<T>;
    /**
     * When using the PostgreSQL database driver, one should call end on the connection pool
     * after the pool has been used.
     *
     * @returns { undefined } `undefined` on success
     */
    destroyPool(): Promise<undefined>;
}