content: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to you 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 org.apache.calcite.server;
  
  import org.apache.calcite.jdbc.CalcitePrepare;
  import org.apache.calcite.sql.SqlNode;
  
  /**
   * Executes DDL commands.
   */
  public interface DdlExecutor {
    /** DDL executor that cannot handle any DDL. */
    DdlExecutor USELESS = (context, node) -> {
      throw new UnsupportedOperationException("DDL not supported: " + node);
    };
  
    /** Executes a DDL statement.
     *
     * <p>The statement identified itself as DDL in the
     * {@link org.apache.calcite.jdbc.CalcitePrepare.ParseResult#kind} field. */
    void executeDdl(CalcitePrepare.Context context, SqlNode node);
  }
  