import { IClause } from '../interfaces/i-clause.interface';
import { QueryPart } from './query-part.model';
/**
 * @public
 *
 * @class Clause
 *
 * @description
 * This entity is a single clause for where statement.
 *
 * @example
 * ```typescript
 * // Create a group of clauses
 * const group = new ClauseGroup();
 *
 * // create clause to get Todo item where isDone === false
 * const doneClause = new Clause();
 * doneClause.key = 'isDone';
 * doneClause.value = false;
 * group.add(doneClause);
 *
 * // create clause to get Todo item where dueDate <= now
 * const dueDateClause = new Clause();
 * dueDateClause.key = 'dueDate';
 * dueDateClause.value = (new Date()).getTime();
 * dueDateClause.comparator = Clause.COMPARATORS.LTE;
 * group.add(dueDateClause);
 *
 * // start select clause
 * Select(Todo).where(group).exec().subscribe((QueryResult<Todo>) => {
 *      // do something with the result...
 * }, (err) => {
 *      // do something with the error...
 * });
 * ```
 *
 * @author  Olivier Margarit
 * @since   0.1
 */
export declare class Clause implements IClause {
    /**
     * @public
     * @property {string} operator is used as join clause condition
     *
     * @default ClauseOperators.AND
     */
    operator: string;
    private keyValue;
    /**
     * @public
     * @property key is table column name corresponding to the field
     * to compare with
     */
    /**
     * @public
     * @method key is table column name corresponding to the field
     * to compare with. Since 0.2, key support complex values. You can use an appended key with
     * [optional]operator + [optional]not + column name + [optional]comparator with space separator
     * or double underscore (__).
     * Be carefull, get key will not return the value set for key. The get method only retrieve the column
     * informations.
     *
     * @example:
     * ```typescript
     *  // function to quickly get current timestamp
     *  function now(): number {
     *      return (new Date()).getTime()
     *  }
     *
     *  // Select all done or passed todo
     *  Select(Todo).where({isDone: true, or__dueDate__lt: now()}).subcribe((qr: QueryResult<Todo>) => {
     *      const ids = <number[]>[];
     *      for (let i = 0; i < qr.rows.length; i++) {
     *          // check if todo really need to be deleted ...
     *          ids.push(qr.rows.item(i).id);
     *      }
     *
     *      Delete(Todo).where(id__in:ids).exec().subscribe(() => {
     *          // todos are delete
     *      }, (err) => {
     *          console.error(err);
     *      })
     *  }, (err) => {
     *      console.error(err);
     *  });
     *
     *  // delete directly without check
     *  Delete(Todo).where({isDone: true, or__dueDate__lt: now()}).subcribe(() => {
     *      // delete done
     *  }, (err) => {
     *      console.error(err);
     *  });
     * ```
     */
    key: string;
    /**
     * @public
     * @property {any} value is the column value to compare with
     */
    value: any;
    /**
     * @public
     * @property {boolean} not is an additionnal operator to invert condition
     */
    not: boolean;
    /**
     * @public
     * @property {string} comparator is a comparator that define the type of
     * relation with the value to compare with and the result.
     *
     * @default ClauseComparators.EQ
     */
    comparator: string;
    /**
     * @public
     * @constructor create a new instance of Clause
     * @param {string} key the clause key
     * @param {any} value the clause value
     *
     * @since 0.2
     */
    constructor(key?: string, value?: any);
    /**
     * @public
     * @method build should be removed to be a part of the private API
     *
     * @return {QueryPart} of the query with the string part and
     *          clauses params.
     */
    build(): QueryPart;
}