export interface CompiledSql {
    sql: string;
    params: (string | number)[];
}
/**
 * `SELECT count(*)` for one row selection, or null when the query names
 * something the projection cannot answer for.
 *
 * @param blocks the `from:` of the selection — one table per block, UNION ALLed
 *   so a multi-block selection counts once across all of them, exactly as
 *   `blocks.flatMap(rowsOf)` does in the evaluator.
 */
export declare function sqlCountFor(def: {
    blocks: Record<string, {
        identity?: string;
        columns: {
            key: string;
            type?: string;
        }[];
    }>;
}, blocks: string[], where?: string): CompiledSql | null;