/**
 * SQL Mode 2 — Entry Point
 *
 * SqlEngine class wires parsing, planning, and execution together.
 * Exposes a single `execute()` method that StrictDB.sql() delegates to.
 */
import type { SqlOptions, SqlMode2Result } from './types.js';
import type { Backend, OperationReceipt } from '../types.js';
import { type SqlExecutorAdapter } from './executor.js';
export type { SqlOptions, SqlMode2Result } from './types.js';
export declare class SqlEngine {
    /**
     * Execute a SQL string against MongoDB.
     */
    static execute(sql: string, options: SqlOptions | undefined, backend: Backend, adapter: SqlExecutorAdapter, rawExecutor?: (sql: string, params?: unknown[]) => Promise<unknown>): Promise<SqlMode2Result | OperationReceipt>;
    /**
     * Execute a UNION / UNION ALL query.
     * Walks the _next chain, builds a plan for each SELECT, runs in parallel, merges.
     */
    private static executeUnion;
    /**
     * Execute a transaction block (BEGIN...COMMIT).
     */
    private static executeTransaction;
}
//# sourceMappingURL=index.d.ts.map