import Transport from 'winston-transport';
export declare enum ClientType {
    'mssql' = 0,
    'mysql2' = 1,
    'pg' = 2
}
export interface SqlTransportOptions {
    client: keyof typeof ClientType;
    connection: any;
    defaultMeta?: any;
    label?: string;
    level?: string;
    name?: string;
    silent?: boolean;
    tableName?: string;
}
export interface SqlTransport extends SqlTransportOptions {
    client: any;
    defaultMeta: any;
    label: string;
    level: string;
    name: string;
    silent: boolean;
    tableName: string;
}
export interface QueryOptions {
    fields?: string[];
    from?: Date | string;
    order?: string;
    rows?: number;
    until?: Date | string;
}
export declare class SqlTransport extends Transport {
    /**
     * Constructor for the universal transport object.
     * @constructor
     * @param {Object} options
     * @param {string} options.client - Database client
     * @param {string} options.connection - Database connection uri | object
     * @param {string} [options.label] - Label stored with entry object if defined.
     * @param {string} [options.level=info] - Level of messages that this transport
     * should log.
     * @param {string} [options.name] - Transport instance identifier. Useful if you
     * need to create multiple universal transports.
     * @param {boolean} [options.silent=false] - Boolean flag indicating whether to
     * suppress output.
     * @param {string} [options.tableName=winston_logs] - The name of the table you
     * want to store log messages in.
     */
    constructor(options: SqlTransportOptions);
    /**
     * Create logs table.
     * @return {Promise} result of creation within a Promise
     */
    init(): Promise<any>;
    /**
     * End the connection
     * Return a Promise which resolves when all queries are finished and the underlying connections are closed.
     * @return {Promise} result within a Promise
     */
    end(): Promise<any>;
    /**
     * Flush all logs
     * Return a Promise which resolves when all logs are finished.
     * @return {Promise} result within a Promise
     */
    flush(): Promise<any>;
    /**
     * Core logging method exposed to Winston. Metadata is optional.
     * @param {Object} info
     * @param {string} [info.level] - Level at which to log the message.
     * @param {string} [info.message] - Message to log
     * @param {Function} callback - Continuation to respond to when complete.
     */
    log(info: any, callback: (e: unknown, data: any) => void): void;
    /**
     * Query the transport. Options object is optional.
     * @param {Object} options - Loggly-like query options for this instance.
     * @param {string} [options.from] - Start time for the search.
     * @param {string} [options.until=now] - End time for the search. Defaults to "now".
     * @param {string} [options.rows=100] - Limited number of rows returned by search. Defaults to 100.
     * @param {string} [options.order=desc] - Direction of results returned, either "asc" or "desc".
     * @param {string[]} [options.fields=[]]
     * @param {Function} callback - Continuation to respond to when complete.
     */
    query(options: QueryOptions, callback: (e: unknown, data: any) => void): void;
}