import { ForeignCommand } from './Command';
/**
 * Fluent configuration of a foreign-key constraint, returned by
 * `table.foreign(...)`:
 *
 *   table.foreign('userId').references('id').on('users').onDelete('cascade')
 *
 * It mutates the underlying ForeignCommand held by the Blueprint, so every
 * chained call keeps configuring the same constraint.
 */
export declare class ForeignKeyDefinition {
    private readonly command;
    constructor(command: ForeignCommand);
    /** The referenced column(s) on the foreign table. */
    references(columns: string | string[]): this;
    /** The referenced (foreign) table. */
    on(table: string): this;
    /** ON DELETE action (e.g. 'cascade', 'set null', 'restrict', 'no action'). */
    onDelete(action: string): this;
    /** ON UPDATE action. */
    onUpdate(action: string): this;
    /** Sets an explicit constraint name. */
    name(name: string): this;
    cascadeOnDelete(): this;
    restrictOnDelete(): this;
    nullOnDelete(): this;
    cascadeOnUpdate(): this;
    restrictOnUpdate(): this;
}