ZDelete.java

/*
 * This file is part of Zql.
 *
 * Zql is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Zql is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Zql.  If not, see <http://www.gnu.org/licenses/>.
 */

package org.gibello.zql;

import java.io.*;
import java.util.*;

/**
 * ZDelete: an SQL DELETE statement.<br>
 * SQL Syntax: DELETE [from] table [where Expression];
 */
public class ZDelete implements ZStatement {

  String table_;
  ZExp where_ = null;

  /**
   * Create a DELETE statement on a given table
   * @param tab the table name
   */
  public ZDelete(String tab) {
    table_ = new String(tab);
  }

  /**
   * Add a WHERE clause to the DELETE statement
   * @param w An SQL expression compatible with a WHERE clause
   */
  public void addWhere(ZExp w) { where_ = w; }

  /**
   * @return The table concerned by the DELETE statement.
   */
  public String getTable() { return table_; }

  /**
   * @return The SQL Where clause of the DELETE statement (an SQL Expression
   * or Subquery, compatible with an SQL WHERE clause).
   */
  public ZExp getWhere() { return where_; }

  public String toString() {
    StringBuffer buf = new StringBuffer("delete ");
    if(where_ != null) buf.append("from ");
    buf.append(table_);
    if(where_ != null) buf.append(" where " + where_.toString());
    return buf.toString();
  }
};