content: /*
   * Copyright 1999-2017 Alibaba Group Holding Ltd.
   *
   * 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.
   */
  package com.alibaba.druid.sql.ast.statement;
  
  import com.alibaba.druid.DbType;
  import com.alibaba.druid.sql.ast.SQLCommentHint;
  import com.alibaba.druid.sql.ast.SQLExpr;
  import com.alibaba.druid.sql.ast.SQLObject;
  import com.alibaba.druid.sql.ast.SQLStatementImpl;
  import com.alibaba.druid.sql.visitor.SQLASTVisitor;
  
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.List;
  
  public class SQLSelectStatement extends SQLStatementImpl {
      protected SQLSelect select;
  
      public SQLSelectStatement() {
      }
  
      public SQLSelectStatement(DbType dbType) {
          super(dbType);
      }
  
      public SQLSelectStatement(SQLSelect select) {
          this.setSelect(select);
      }
  
      public SQLSelectStatement(SQLSelect select, DbType dbType) {
          this(dbType);
          this.setSelect(select);
      }
  
      public SQLSelect getSelect() {
          return this.select;
      }
  
      public void setSelect(SQLSelect select) {
          if (select != null) {
              select.setParent(this);
          }
          this.select = select;
      }
  
      public void output(StringBuilder buf) {
          this.select.output(buf);
      }
  
      protected void accept0(SQLASTVisitor visitor) {
          if (visitor.visit(this)) {
              if (this.select != null) {
                  this.select.accept(visitor);
              }
          }
          visitor.endVisit(this);
      }
  
      public SQLSelectStatement clone() {
          SQLSelectStatement x = new SQLSelectStatement();
          x.dbType = dbType;
          x.afterSemi = afterSemi;
          if (select != null) {
              x.setSelect(select.clone());
          }
          if (headHints != null) {
              for (SQLCommentHint h : headHints) {
                  SQLCommentHint h2 = h.clone();
                  h2.setParent(x);
                  if (x.headHints == null) {
                      x.headHints = new ArrayList<SQLCommentHint>(headHints.size());
                  }
                  x.headHints.add(h2);
              }
          }
          return x;
      }
  
      @Override
      public List<SQLObject> getChildren() {
          return Collections.<SQLObject>singletonList(select);
      }
  
      @Override
      public boolean equals(Object o) {
          if (this == o) {
              return true;
          }
          if (o == null || getClass() != o.getClass()) {
              return false;
          }
  
          SQLSelectStatement that = (SQLSelectStatement) o;
  
          return select != null ? select.equals(that.select) : that.select == null;
      }
  
      @Override
      public int hashCode() {
          return select != null ? select.hashCode() : 0;
      }
  
      public List<String> computeSelecteListAlias() {
          return select.computeSelecteListAlias();
      }
  
      public boolean addWhere(SQLExpr where) {
          return select.addWhere(where);
      }
  
      public void addBeforeComment(String comment) {
          if (headHints == null && attributes == null && select.hints == null && select.getBeforeCommentsDirect() == null) {
              SQLSelectQueryBlock queryBlock = select.getQueryBlock();
              List<String> queryBlockBeforeComments = queryBlock.getBeforeCommentsDirect();
              if (queryBlockBeforeComments != null) {
                  queryBlockBeforeComments.add(comment);
                  return;
              }
          }
          super.addBeforeComment(comment);
      }
  }
  