content: /*
   * Copyright 1999-2012 Alibaba Group.
   *  
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *  
   *      http://www.apache.org/licenses/LICENSE-2.0
   *  
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  /**
   * (created at 2011-1-29)
   */
  package com.alibaba.cobar.parser.ast.stmt.dml;
  
  import java.util.LinkedList;
  import java.util.List;
  
  import com.alibaba.cobar.parser.ast.fragment.Limit;
  import com.alibaba.cobar.parser.ast.fragment.OrderBy;
  import com.alibaba.cobar.parser.visitor.SQLASTVisitor;
  
  /**
   * @author <a href="mailto:shuo.qius@alibaba-inc.com">QIU Shuo</a>
   */
  public class DMLSelectUnionStatement extends DMLQueryStatement {
      /** might be {@link LinkedList} */
      private final List<DMLSelectStatement> selectStmtList;
      /**
       * <code>Mixed UNION types are treated such that a DISTINCT union overrides any ALL union to its left</code>
       * <br/>
       * 0 means all relations of selects are union all<br/>
       * last index of {@link #selectStmtList} means all relations of selects are
       * union distinct<br/>
       */
      private int firstDistinctIndex = 0;
      private OrderBy orderBy;
      private Limit limit;
  
      public DMLSelectUnionStatement(DMLSelectStatement select) {
          super();
          this.selectStmtList = new LinkedList<DMLSelectStatement>();
          this.selectStmtList.add(select);
      }
  
      public DMLSelectUnionStatement addSelect(DMLSelectStatement select, boolean unionAll) {
          selectStmtList.add(select);
          if (!unionAll) {
              firstDistinctIndex = selectStmtList.size() - 1;
          }
          return this;
      }
  
      public DMLSelectUnionStatement setOrderBy(OrderBy orderBy) {
          this.orderBy = orderBy;
          return this;
      }
  
      public DMLSelectUnionStatement setLimit(Limit limit) {
          this.limit = limit;
          return this;
      }
  
      public List<DMLSelectStatement> getSelectStmtList() {
          return selectStmtList;
      }
  
      public int getFirstDistinctIndex() {
          return firstDistinctIndex;
      }
  
      public OrderBy getOrderBy() {
          return orderBy;
      }
  
      public Limit getLimit() {
          return limit;
      }
  
      @Override
      public void accept(SQLASTVisitor visitor) {
          visitor.visit(this);
      }
  }
  