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.sql;
  
  import org.apache.calcite.sql.fun.SqlStdOperatorTable;
  import org.apache.calcite.sql.parser.SqlParserPos;
  import org.apache.calcite.sql.validate.SqlValidator;
  
  import java.util.Collections;
  
  /**
   * SqlProcedureCallOperator represents the CALL statement. It takes a single
   * operand which is the real SqlCall.
   */
  public class SqlProcedureCallOperator extends SqlPrefixOperator {
    //~ Constructors -----------------------------------------------------------
  
    public SqlProcedureCallOperator() {
      super("CALL", SqlKind.PROCEDURE_CALL, 0, null, null, null);
    }
  
    //~ Methods ----------------------------------------------------------------
  
    // override SqlOperator
    @Override public SqlNode rewriteCall(SqlValidator validator, SqlCall call) {
      // for now, rewrite "CALL f(x)" to "SELECT f(x) FROM VALUES(0)"
      // TODO jvs 18-Jan-2005:  rewrite to SELECT * FROM TABLE f(x)
      // once we support function calls as tables
      return new SqlSelect(SqlParserPos.ZERO,
          null,
          new SqlNodeList(
              Collections.singletonList(call.operand(0)),
              SqlParserPos.ZERO),
          SqlStdOperatorTable.VALUES.createCall(
              SqlParserPos.ZERO,
              SqlStdOperatorTable.ROW.createCall(
                  SqlParserPos.ZERO,
                  SqlLiteral.createExactNumeric("0", SqlParserPos.ZERO))),
          null,
          null,
          null,
          null,
          null,
          null,
          null,
          null,
          null);
    }
  }
  