import { ServiceBase } from '@opra/core';
import { SqbClient, SqbConnection } from '@sqb/connect';
/**
 * Namespace for SqbServiceBase types and options.
 */
export declare namespace SqbServiceBase {
    /**
     * Options for initializing SqbServiceBase.
     */
    interface Options extends ServiceBase.Options {
        /**
         * The SQB client or connection used by this service.
         */
        db?: SqbServiceBase['db'];
    }
}
/**
 * Base class for services using SQB (SQL Builder) for database operations.
 */
export declare class SqbServiceBase extends ServiceBase {
    /**
     * The SQB client or connection used by this service.
     */
    db?: (SqbClient | SqbConnection) | ((_this: this) => SqbClient | SqbConnection);
    /**
     * Constructs a new instance.
     *
     * @param options - Options for the service.
     */
    constructor(options?: SqbServiceBase.Options);
    /**
     * Executes the provided callback within a database transaction.
     * If a transaction is already active in the current context, the callback
     * joins it rather than starting a new one.
     *
     * @param callback - The function to execute within the transaction.
     */
    withTransaction<U = any>(callback: (connection: SqbConnection, _this: this) => U): Promise<U>;
    /**
     * Returns the active database connection for the current context.
     *
     * @throws If no database connection is configured.
     */
    getConnection(): SqbConnection | SqbClient | Promise<SqbConnection | SqbClient>;
}