/**
 * Duck-typed protocol interfaces for query builders.
 *
 * These interfaces define the minimal contract that a query builder must satisfy
 * to work with the semantic dataset client. The @hypequery/clickhouse `createQueryBuilder`
 * return value satisfies `QueryBuilderFactoryLike` structurally — no explicit
 * `implements` is needed.
 *
 * This keeps @hypequery/serve DB-agnostic while enabling first-class builder usage.
 */
/** A chainable query builder instance (what `.table(name)` returns). */
export interface QueryBuilderLike {
    select(columns: string[] | string): QueryBuilderLike;
    sum(column: string, alias?: string): QueryBuilderLike;
    count(column: string, alias?: string): QueryBuilderLike;
    countDistinct(column: string, alias?: string): QueryBuilderLike;
    avg(column: string, alias?: string): QueryBuilderLike;
    min(column: string, alias?: string): QueryBuilderLike;
    max(column: string, alias?: string): QueryBuilderLike;
    /** Value of `column` on the row where `argColumn` is greatest. */
    argMax?(column: string, argColumn: string, alias?: string): QueryBuilderLike;
    /** Value of `column` on the row where `argColumn` is smallest. */
    argMin?(column: string, argColumn: string, alias?: string): QueryBuilderLike;
    /** Approximate percentile of `column` at `level` in [0, 1]. */
    quantile?(column: string, level: number, alias?: string): QueryBuilderLike;
    /** Sample standard deviation of `column`. */
    stddev?(column: string, alias?: string): QueryBuilderLike;
    /** Sample variance of `column`. */
    variance?(column: string, alias?: string): QueryBuilderLike;
    where(column: string, operator: string, value: unknown): QueryBuilderLike;
    leftJoin(table: string, leftColumn: string, rightColumn: string, alias?: string, on?: QueryBuilderJoinCondition | QueryBuilderJoinCondition[]): QueryBuilderLike;
    /**
     * Optional single-match LEFT JOIN (ClickHouse `LEFT ANY JOIN`). When a
     * builder provides it, relationship joins use it so duplicate target join
     * keys cannot fan out aggregates; otherwise `leftJoin` is used.
     */
    leftAnyJoin?(table: string, leftColumn: string, rightColumn: string, alias?: string, on?: QueryBuilderJoinCondition | QueryBuilderJoinCondition[]): QueryBuilderLike;
    groupBy(columns: string | string[]): QueryBuilderLike;
    orderBy(column: string, direction?: 'ASC' | 'DESC'): QueryBuilderLike;
    limit(count: number): QueryBuilderLike;
    offset(count: number): QueryBuilderLike;
    toSQLWithParams(): {
        sql: string;
        parameters: unknown[];
    };
    execute<T = Record<string, unknown>>(): Promise<T[]>;
}
export interface QueryBuilderJoinCondition {
    column: string;
    operator: string;
    value: unknown;
}
/** A query builder factory (what `createQueryBuilder(config)` returns). */
export interface QueryBuilderFactoryLike {
    table(name: string): QueryBuilderLike;
    rawQuery<T = Record<string, unknown>>(sql: string, params?: unknown[]): Promise<T[]>;
}
/**
 * Acceptance shape for query builder factories at public entry points.
 *
 * Schema-typed builders (e.g. `createQueryBuilder<Schema>` from
 * `@hypequery/clickhouse`) narrow column parameters to literal unions, type
 * `execute()` rows concretely, and overload `where`, so they cannot
 * structurally satisfy `QueryBuilderFactoryLike` even though they honor its
 * runtime contract. This looser shape admits both protocol-shaped and
 * schema-typed builders; entry points adapt with `toQueryBuilderFactory`.
 */
export interface QueryBuilderFactoryCompatible {
    table(name: never): unknown;
    rawQuery(sql: string, params?: never): Promise<unknown>;
}
/** Any query builder factory accepted by public entry points. */
export type QueryBuilderFactoryInput = QueryBuilderFactoryLike | QueryBuilderFactoryCompatible;
/**
 * Adapts an accepted factory to the internal `QueryBuilderFactoryLike` call
 * contract. Safe because the semantic layer only calls protocol methods with
 * plain strings, which schema-typed builders handle at runtime.
 */
export declare function toQueryBuilderFactory(factory: QueryBuilderFactoryInput): QueryBuilderFactoryLike;
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