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.jdbc;
  
  import org.apache.calcite.adapter.java.JavaTypeFactory;
  import org.apache.calcite.config.CalciteConnectionConfig;
  import org.apache.calcite.jdbc.CalcitePrepare.Context;
  import org.apache.calcite.linq4j.QueryProvider;
  import org.apache.calcite.schema.SchemaPlus;
  
  import org.checkerframework.checker.nullness.qual.Nullable;
  
  import java.sql.Connection;
  import java.sql.SQLException;
  import java.util.Properties;
  
  /**
   * Extension to Calcite's implementation of
   * {@link java.sql.Connection JDBC connection} allows schemas to be defined
   * dynamically.
   *
   * <p>You can start off with an empty connection (no schemas), define one
   * or two schemas, and start querying them.
   *
   * <p>Since a {@code CalciteConnection} implements the linq4j
   * {@link QueryProvider} interface, you can use a connection to execute
   * expression trees as queries.
   */
  public interface CalciteConnection extends Connection, QueryProvider {
    /**
     * Returns the root schema.
     *
     * <p>You can define objects (such as relations) in this schema, and
     * also nested schemas.
     *
     * @return Root schema
     */
    SchemaPlus getRootSchema();
  
    /**
     * Returns the type factory.
     *
     * @return Type factory
     */
    JavaTypeFactory getTypeFactory();
  
    /**
     * Returns an instance of the connection properties.
     *
     * <p>NOTE: The resulting collection of properties is same collection used
     * by the connection, and is writable, but behavior if you modify the
     * collection is undefined. Some implementations might, for example, see
     * a modified property, but only if you set it before you create a
     * statement. We will remove this method when there are better
     * implementations of stateful connections and configuration.
     *
     * @return properties
     */
    Properties getProperties();
  
    // in java.sql.Connection from JDK 1.7, but declare here to allow other JDKs
    @Override void setSchema(String schema) throws SQLException;
  
    // in java.sql.Connection from JDK 1.7, but declare here to allow other JDKs
    @Override @Nullable String getSchema() throws SQLException;
  
    CalciteConnectionConfig config();
  
    /** Creates a context for preparing a statement for execution. */
    Context createPrepareContext();
  }
  