/**
 * Dependency-free `query` adapters for common DB drivers, to plug into createSqlTool.
 *
 * These are structurally typed: you pass an already-created (ideally READ-ONLY) client/pool.
 * No driver is a dependency of this package — install whichever you use in your app.
 *
 * Usage:
 *   import pg from "pg";
 *   const pool = new pg.Pool({ connectionString: READONLY_URL });
 *   const tool = createSqlTool({ query: pgQuery(pool), allowTables: ["orders"] });
 */
/** node-postgres (`pg`) Pool/Client. */
export declare function pgQuery(pool: {
    query: (text: string) => Promise<{
        rows: unknown[];
    }>;
}): (sql: string) => Promise<unknown[]>;
/**
 * `mysql2/promise` connection or pool.
 * Also use this for **TiDB** (MySQL wire-compatible): create a read-only `mysql2` pool
 * pointed at your TiDB endpoint and pass it here.
 */
export declare function mysqlQuery(conn: {
    query: (sql: string) => Promise<[unknown, unknown]>;
}): (sql: string) => Promise<unknown[]>;
/** `better-sqlite3` database (synchronous). */
export declare function sqliteQuery(db: {
    prepare: (sql: string) => {
        all: () => unknown[];
    };
}): (sql: string) => Promise<unknown[]>;