CalciteMetaColumnFactory.java

/*
 * 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.avatica.MetaImpl.MetaColumn;
import org.apache.calcite.schema.Table;

import org.checkerframework.checker.nullness.qual.Nullable;

import java.util.List;

/** Factory for creating instances of {@link MetaColumn}.
 *
 * @see java.sql.DatabaseMetaData#getColumns */
public interface CalciteMetaColumnFactory {
  /** Instantiates a MetaColumn. */
  MetaColumn createColumn(Table table, String tableCat, String tableSchem,
      String tableName, String columnName, int dataType, String typeName,
      Integer columnSize, @Nullable Integer decimalDigits, int numPrecRadix,
      int nullable, Integer charOctetLength, int ordinalPosition,
      String isNullable);

  /** Returns the list of expected column names.
   *
   * <p>The default implementation returns the columns described in the JDBC
   * specification. */
  default List<String> getColumnNames() {
    return CalciteMetaImpl.COLUMN_COLUMNS;
  }

  /** Returns the type of object created. Must be a subclass of MetaColumn. */
  Class<? extends MetaColumn> getMetaColumnClass();

}