schemacrawler.crawl.RetrieverUtility Maven / Gradle / Ivy

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/*
========================================================================
SchemaCrawler
http://www.schemacrawler.com
Copyright (c) 2000-2021, Sualeh Fatehi .
All rights reserved.
------------------------------------------------------------------------

SchemaCrawler is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

SchemaCrawler and the accompanying materials are made available under
the terms of the Eclipse Public License v1.0, GNU General Public License
v3 or GNU Lesser General Public License v3.

You may elect to redistribute this code under any of these licenses.

The Eclipse Public License is available at:
http://www.eclipse.org/legal/epl-v10.html

The GNU General Public License v3 and the GNU Lesser General Public
License v3 are available at:
http://www.gnu.org/licenses/

========================================================================
*/

package schemacrawler.crawl;

import static java.util.Objects.requireNonNull;
import static us.fatehi.utility.Utility.isBlank;

import java.util.Optional;
import java.util.logging.Level;

import schemacrawler.SchemaCrawlerLogger;
import schemacrawler.schema.Catalog;
import schemacrawler.schema.Column;
import schemacrawler.schema.Schema;
import schemacrawler.schema.Table;
import schemacrawler.schemacrawler.SchemaReference;
import us.fatehi.utility.UtilityMarker;
import us.fatehi.utility.string.StringFormat;

@UtilityMarker
public final class RetrieverUtility {

  private static final SchemaCrawlerLogger LOGGER =
      SchemaCrawlerLogger.getLogger(RetrieverUtility.class.getName());

  static String constructForeignKeyName(final Table pkTable, final Table fkTable) {
    requireNonNull(pkTable, "No referenced table provided");
    requireNonNull(fkTable, "No referencing table provided");

    final String pkHex = Integer.toHexString(pkTable.getFullName().hashCode());
    final String fkHex = Integer.toHexString(fkTable.getFullName().hashCode());
    final String foreignKeyName = String.format("SC_%s_%s", pkHex, fkHex).toUpperCase();
    return foreignKeyName;
  }

  static Column lookupOrCreateColumn(
      final Catalog catalog, final Schema schema, final String tableName, final String columnName) {

    if (isBlank(columnName)) {
      return null;
    }

    requireNonNull(catalog, "No catalog provided");
    requireNonNull(schema, "No schema provided");

    Column column = null;
    final Optional columnOptional =
        catalog.lookupColumn(schema, tableName, columnName);
    if (columnOptional.isPresent()) {
      column = columnOptional.get();
    }

    if (column == null) {
      // Create the table and column, but do not add it to the schema
      final Table table = new TablePartial(schema, tableName);
      column = new ColumnPartial(table, columnName);
      ((TablePartial) table).addColumn(column);

      LOGGER.log(
          Level.FINER,
          new StringFormat("Creating partial column for a column reference <%s>", column));
    }
    return column;
  }

  /**
   * Looks up a column in the database. If the column and table are not found, they are created, and
   * added to the schema. This is prevent foreign key relationships from having a null pointer.
   */
  static Column lookupOrCreateColumn(
      final Catalog catalog,
      final String catalogName,
      final String schemaName,
      final String tableName,
      final String columnName) {
    return lookupOrCreateColumn(
        catalog, new SchemaReference(catalogName, schemaName), tableName, columnName);
  }

  private RetrieverUtility() {
    // Prevent instantiaton
  }
}