/*
// Licensed to Julian Hyde under one or more contributor license
// agreements. See the NOTICE file distributed with this work for
// additional information regarding copyright ownership.
//
// Julian Hyde 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 net.hydromatic.optiq.jdbc;

import net.hydromatic.linq4j.function.Function0;
import net.hydromatic.optiq.runtime.ColumnMetaData;
import net.hydromatic.optiq.runtime.Cursor;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Collections;
import java.util.List;

/**
 * Utility methods, mainly concerning error-handling.
 */
public class Helper {
  public static final Helper INSTANCE = new Helper();

  private Helper() {
  }

  public RuntimeException todo() {
    return new RuntimeException("todo: implement this method");
  }

  public RuntimeException wrap(String message, Exception e) {
    return new RuntimeException(message, e);
  }

  public SQLException createException(String message, Exception e) {
    return new SQLException(message, e);
  }

  public SQLException createException(String message) {
    return new SQLException(message);
  }

  public SQLException toSQLException(SQLException exception) {
    return exception;
  }

  /** Creates an empty result set. Useful for JDBC metadata methods that are
   * not implemented or which query entities that are not supported (e.g.
   * triggers in Lingual). */
  public ResultSet createEmptyResultSet(OptiqConnectionImpl connection) {
    try {
      return connection.driver.factory.newResultSet(
          connection.createStatement(),
          Collections.<ColumnMetaData>emptyList(),
          new Function0<Cursor>() {
            public Cursor apply() {
              return new Cursor() {
                public List<Accessor> createAccessors(
                    List<ColumnMetaData> types) {
                  assert types.isEmpty();
                  return Collections.emptyList();
                }

                public boolean next() {
                  return false;
                }
              };
            }
          }).execute();
    } catch (SQLException e) {
      throw new RuntimeException(e);
    }
  }
}

// End Helper.java

/*
// Licensed to Julian Hyde under one or more contributor license
// agreements. See the NOTICE file distributed with this work for
// additional information regarding copyright ownership.
//
// Julian Hyde 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 net.hydromatic.optiq.jdbc;

import net.hydromatic.linq4j.function.Function0;
import net.hydromatic.optiq.runtime.ColumnMetaData;
import net.hydromatic.optiq.runtime.Cursor;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Collections;
import java.util.List;

/**
 * Utility methods, mainly concerning error-handling.
 */
public class Helper {
  public static final Helper INSTANCE = new Helper();

  private Helper() {
  }

  public RuntimeException todo() {
    return new RuntimeException("todo: implement this method");
  }

  public RuntimeException wrap(String message, Exception e) {
    return new RuntimeException(message, e);
  }

  public SQLException createException(String message, Exception e) {
    return new SQLException(message, e);
  }

  public SQLException createException(String message) {
    return new SQLException(message);
  }

  public SQLException toSQLException(SQLException exception) {
    return exception;
  }

  /** Creates an empty result set. Useful for JDBC metadata methods that are
   * not implemented or which query entities that are not supported (e.g.
   * triggers in Lingual). */
  public ResultSet createEmptyResultSet(OptiqConnection connection) {
    try {
      final OptiqConnectionImpl connection1 = (OptiqConnectionImpl) connection;
      return connection1.driver.factory.newResultSet(
          connection1.createStatement(),
          Collections.<ColumnMetaData>emptyList(),
          new Function0<Cursor>() {
            public Cursor apply() {
              return new Cursor() {
                public List<Accessor> createAccessors(
                    List<ColumnMetaData> types) {
                  assert types.isEmpty();
                  return Collections.emptyList();
                }

                public boolean next() {
                  return false;
                }
              };
            }
          }).execute();
    } catch (SQLException e) {
      throw new RuntimeException(e);
    }
  }
}

// End Helper.java

Change signature of createEmptyResultSet; OptiqConnectionImpl isn't public, so method couldn't be called from outside package.