import { BaseDuckDBType } from './BaseDuckDBType';
import type { DuckDBType } from './DuckDBType';
import { DuckDBLogicalType } from '../DuckDBLogicalType';
import { DuckDBTypeId } from '../DuckDBTypeId';
import { Json } from '../Json';
export declare class DuckDBUnionType extends BaseDuckDBType<DuckDBTypeId.UNION> {
    readonly memberTags: readonly string[];
    readonly tagMemberIndexes: Readonly<Record<string, number>>;
    readonly memberTypes: readonly DuckDBType[];
    constructor(memberTags: readonly string[], memberTypes: readonly DuckDBType[], alias?: string);
    memberIndexForTag(tag: string): number;
    memberTypeForTag(tag: string): DuckDBType;
    get memberCount(): number;
    toString(): string;
    toLogicalType(): DuckDBLogicalType;
    toJson(): Json;
}
export declare function UNION(members: Record<string, DuckDBType>, alias?: string): DuckDBUnionType;