schemacrawler.crawl.ForeignKeyRetriever Maven / Gradle / Ivy
/*
========================================================================
SchemaCrawler
http://www.schemacrawler.com
Copyright (c) 2000-2020, 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 schemacrawler.schemacrawler.InformationSchemaKey.FOREIGN_KEYS;
import static schemacrawler.schemacrawler.SchemaInfoMetadataRetrievalStrategy.foreignKeysRetrievalStrategy;
import static us.fatehi.utility.Utility.isBlank;
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Arrays;
import java.util.Optional;
import java.util.logging.Level;
import schemacrawler.SchemaCrawlerLogger;
import schemacrawler.schema.Column;
import schemacrawler.schema.ForeignKeyDeferrability;
import schemacrawler.schema.ForeignKeyUpdateRule;
import schemacrawler.schema.Schema;
import schemacrawler.schema.Table;
import schemacrawler.schema.View;
import schemacrawler.schemacrawler.InformationSchemaViews;
import schemacrawler.schemacrawler.Query;
import schemacrawler.schemacrawler.SchemaCrawlerOptions;
import schemacrawler.schemacrawler.SchemaCrawlerSQLException;
import schemacrawler.schemacrawler.SchemaReference;
import schemacrawler.utility.MetaDataUtility;
import us.fatehi.utility.string.StringFormat;
/**
* A retriever uses database metadata to get the details about the database
* forign keys.
*
* @author Sualeh Fatehi
*/
final class ForeignKeyRetriever
extends AbstractRetriever
{
private static final SchemaCrawlerLogger LOGGER =
SchemaCrawlerLogger.getLogger(ForeignKeyRetriever.class.getName());
ForeignKeyRetriever(final RetrieverConnection retrieverConnection,
final MutableCatalog catalog,
final SchemaCrawlerOptions options)
{
super(retrieverConnection, catalog, options);
}
void retrieveForeignKeys(final NamedObjectList allTables)
throws SQLException
{
requireNonNull(allTables, "No tables provided");
switch (getRetrieverConnection().get(foreignKeysRetrievalStrategy))
{
case data_dictionary_all:
LOGGER.log(Level.INFO,
"Retrieving foreign keys, using fast data dictionary retrieval");
retrieveForeignKeysFromDataDictionary();
break;
case metadata:
LOGGER.log(Level.INFO, "Retrieving foreign keys");
retrieveForeignKeysFromMetadata(allTables);
break;
default:
break;
}
}
private void createForeignKeys(final MetadataResultSet results,
final NamedObjectList foreignKeys)
throws SQLException
{
while (results.next())
{
final String foreignKeyName = results.getString("FK_NAME");
LOGGER.log(Level.FINE,
new StringFormat("Retrieving foreign key: %s",
foreignKeyName));
final String pkTableCatalogName =
normalizeCatalogName(results.getString("PKTABLE_CAT"));
final String pkTableSchemaName =
normalizeSchemaName(results.getString("PKTABLE_SCHEM"));
final String pkTableName = results.getString("PKTABLE_NAME");
final String pkColumnName = results.getString("PKCOLUMN_NAME");
final String fkTableCatalogName =
normalizeCatalogName(results.getString("FKTABLE_CAT"));
final String fkTableSchemaName =
normalizeSchemaName(results.getString("FKTABLE_SCHEM"));
final String fkTableName = results.getString("FKTABLE_NAME");
final String fkColumnName = results.getString("FKCOLUMN_NAME");
final int keySequence = results.getInt("KEY_SEQ", 0);
final ForeignKeyUpdateRule updateRule =
results.getEnumFromId("UPDATE_RULE", ForeignKeyUpdateRule.unknown);
final ForeignKeyUpdateRule deleteRule =
results.getEnumFromId("DELETE_RULE", ForeignKeyUpdateRule.unknown);
final ForeignKeyDeferrability deferrability =
results.getEnumFromId("DEFERRABILITY", ForeignKeyDeferrability.unknown);
final Column pkColumn = lookupOrCreateColumn(pkTableCatalogName,
pkTableSchemaName,
pkTableName,
pkColumnName);
final Column fkColumn = lookupOrCreateColumn(fkTableCatalogName,
fkTableSchemaName,
fkTableName,
fkColumnName);
final boolean isPkColumnPartial = pkColumn instanceof ColumnPartial;
final boolean isFkColumnPartial = fkColumn instanceof ColumnPartial;
if (pkColumn == null
|| fkColumn == null
|| isFkColumnPartial && isPkColumnPartial)
{
continue;
}
final String specificName;
if (isBlank(foreignKeyName))
{
specificName =
MetaDataUtility.constructForeignKeyName(pkColumn, fkColumn);
}
else
{
specificName = foreignKeyName;
}
final Optional foreignKeyOptional =
foreignKeys.lookup(Arrays.asList(foreignKeyName, specificName));
final MutableForeignKey foreignKey;
if (foreignKeyOptional.isPresent())
{
foreignKey = foreignKeyOptional.get();
}
else
{
foreignKey = new MutableForeignKey(foreignKeyName);
foreignKey.setSpecificName(specificName);
// Specific name needs to be set before the foreign key is added
// to the list, since it is part of the unique lookup key
foreignKeys.add(foreignKey);
}
foreignKey.addColumnReference(keySequence, pkColumn, fkColumn);
foreignKey.setUpdateRule(updateRule);
foreignKey.setDeleteRule(deleteRule);
foreignKey.setDeferrability(deferrability);
foreignKey.addAttributes(results.getAttributes());
if (fkColumn instanceof MutableColumn)
{
((MutableColumn) fkColumn).setReferencedColumn(pkColumn);
((MutableTable) fkColumn.getParent()).addForeignKey(foreignKey);
}
else if (isFkColumnPartial)
{
((ColumnPartial) fkColumn).setReferencedColumn(pkColumn);
((TablePartial) fkColumn.getParent()).addForeignKey(foreignKey);
}
if (pkColumn instanceof MutableColumn)
{
((MutableTable) pkColumn.getParent()).addForeignKey(foreignKey);
}
else if (isPkColumnPartial)
{
((TablePartial) pkColumn.getParent()).addForeignKey(foreignKey);
}
}
}
/**
* 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.
*/
private Column lookupOrCreateColumn(final String catalogName,
final String schemaName,
final String tableName,
final String columnName)
{
Column column = null;
final Optional tableOptional =
catalog.lookupTable(Arrays.asList(catalogName, schemaName, tableName));
if (tableOptional.isPresent())
{
final Table table = tableOptional.get();
final Optional columnOptional =
table.lookupColumn(columnName);
if (columnOptional.isPresent())
{
column = columnOptional.get();
}
}
if (column == null && !isBlank(columnName))
{
// Create the table and column, but do not add it to the schema
final Schema schema = new SchemaReference(catalogName, schemaName);
final Table table = new TablePartial(schema, tableName);
column = new ColumnPartial(table, columnName);
((TablePartial) table).addColumn(column);
LOGGER.log(Level.FINER,
new StringFormat(
"Creating column reference for a column that is referenced by a foreign key <%s>",
column));
}
return column;
}
private void retrieveForeignKeysFromDataDictionary()
throws SchemaCrawlerSQLException
{
final InformationSchemaViews informationSchemaViews =
getRetrieverConnection().getInformationSchemaViews();
if (!informationSchemaViews.hasQuery(FOREIGN_KEYS))
{
LOGGER.log(Level.FINE,
"Extended foreign keys SQL statement was not provided");
return;
}
final NamedObjectList foreignKeys =
new NamedObjectList<>();
final Query fkSql = informationSchemaViews.getQuery(FOREIGN_KEYS);
final Connection connection = getDatabaseConnection();
try (
final Statement statement = connection.createStatement();
final MetadataResultSet results = new MetadataResultSet(fkSql,
statement,
getSchemaInclusionRule())
)
{
results.setDescription("retrieveForeignKeysUsingSql");
createForeignKeys(results, foreignKeys);
}
catch (final SQLException e)
{
throw new SchemaCrawlerSQLException(
"Could not retrieve foreign keys from SQL:\n" + fkSql,
e);
}
}
private void retrieveForeignKeysFromMetadata(final NamedObjectList allTables)
throws SchemaCrawlerSQLException
{
final NamedObjectList foreignKeys =
new NamedObjectList<>();
for (final MutableTable table : allTables)
{
if (table instanceof View)
{
continue;
}
final DatabaseMetaData metaData = getMetaData();
// Get imported foreign keys
try (
final MetadataResultSet results = new MetadataResultSet(metaData.getImportedKeys(
table
.getSchema()
.getCatalogName(),
table
.getSchema()
.getName(),
table.getName()))
)
{
createForeignKeys(results, foreignKeys);
}
catch (final SQLException e)
{
throw new SchemaCrawlerSQLException(
"Could not retrieve foreign keys for table " + table,
e);
}
// We need to get exported keys as well, since if only a single
// table is selected, we have not retrieved it's keys that are
// imported by other tables.
try (
final MetadataResultSet results = new MetadataResultSet(metaData.getExportedKeys(
table
.getSchema()
.getCatalogName(),
table
.getSchema()
.getName(),
table.getName()))
)
{
createForeignKeys(results, foreignKeys);
}
catch (final SQLException e)
{
throw new SchemaCrawlerSQLException(
"Could not retrieve foreign keys for table " + table,
e);
}
}
}
}
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