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SchemaCrawler is an open-source Java API that makes working with database metadata as easy as working with plain old Java objects. SchemaCrawler is also a database schema discovery and comprehension, and schema documentation tool. You can search for database schema objects using regular expressions, and output the schema and data in a readable text format. The output is designed to be diff-ed against other database schemas.
/*
========================================================================
SchemaCrawler
http://www.schemacrawler.com
Copyright (c) 2000-2016, 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 java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Optional;
import java.util.logging.Level;
import java.util.logging.Logger;
import static java.util.Objects.requireNonNull;
import static sf.util.Utility.isBlank;
import schemacrawler.schema.Column;
import schemacrawler.schema.ForeignKey;
import schemacrawler.schema.ForeignKeyDeferrability;
import schemacrawler.schema.ForeignKeyUpdateRule;
import schemacrawler.schema.SchemaReference;
import schemacrawler.schema.Table;
import schemacrawler.schema.View;
import schemacrawler.schemacrawler.InformationSchemaViews;
import schemacrawler.schemacrawler.SchemaCrawlerOptions;
import schemacrawler.schemacrawler.SchemaCrawlerSQLException;
import schemacrawler.utility.MetaDataUtility;
import schemacrawler.utility.Query;
import sf.util.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 Logger LOGGER = Logger
.getLogger(ForeignKeyRetriever.class.getName());
ForeignKeyRetriever(final RetrieverConnection retrieverConnection,
final MutableCatalog catalog,
final SchemaCrawlerOptions options)
throws SQLException
{
super(retrieverConnection, catalog, options);
}
void retrieveForeignKeyDefinitions(final NamedObjectList allTables)
{
requireNonNull(allTables);
final InformationSchemaViews informationSchemaViews = getRetrieverConnection()
.getInformationSchemaViews();
final Connection connection = getDatabaseConnection();
if (!informationSchemaViews.hasExtForeignKeysSql())
{
LOGGER.log(Level.FINE,
"Extended foreign keys SQL statement was not provided");
return;
}
final NamedObjectList allFks = new NamedObjectList<>();
for (final MutableTable table: allTables)
{
for (final ForeignKey foreignKey: table.getForeignKeys())
{
allFks.add((MutableForeignKey) foreignKey);
}
}
final Query extForeignKeysSql = informationSchemaViews
.getExtForeignKeysSql();
try (final Statement statement = connection.createStatement();
final MetadataResultSet results = new MetadataResultSet(extForeignKeysSql,
statement,
getSchemaInclusionRule());)
{
while (results.next())
{
// FOREIGN_KEY_CATALOG, FOREIGN_KEY_SCHEMA, FOREIGN_KEY_TABLE
final String fkName = quotedName(results.getString("FOREIGN_KEY_NAME"));
LOGGER.log(Level.FINER,
new StringFormat("Retrieving foreign key definition, %s",
fkName));
final String definition = results.getString("FOREIGN_KEY_DEFINITION");
final Optional optionalFk = allFks.lookup(fkName);
if (optionalFk.isPresent())
{
final MutableForeignKey fkConstraint = optionalFk.get();
fkConstraint.appendDefinition(definition);
fkConstraint.addAttributes(results.getAttributes());
}
else
{
LOGGER
.log(Level.FINER,
new StringFormat("Could not find foreign key, %s", fkName));
}
}
}
catch (final Exception e)
{
LOGGER.log(Level.WARNING, "Could not retrieve check constraints", e);
}
}
void retrieveForeignKeys(final NamedObjectList allTables)
throws SchemaCrawlerSQLException
{
requireNonNull(allTables);
final InformationSchemaViews informationSchemaViews = getRetrieverConnection()
.getInformationSchemaViews();
if (!informationSchemaViews.hasForeignKeysSql())
{
LOGGER.log(Level.INFO,
"Retrieving foreign keys, using database metadata");
retrieveForeignKeysUsingDatabaseMetadata(allTables);
}
else
{
LOGGER.log(Level.INFO, "Retrieving foreign keys, using SQL");
retrieveForeignKeysUsingSql(informationSchemaViews);
}
}
private void createForeignKeys(final MetadataResultSet results,
final NamedObjectList foreignKeys)
throws SQLException
{
try
{
while (results.next())
{
String foreignKeyName = quotedName(results.getString("FK_NAME"));
LOGGER
.log(Level.FINE,
new StringFormat("Retrieving foreign key: %s", foreignKeyName));
final String pkTableCatalogName = quotedName(results
.getString("PKTABLE_CAT"));
final String pkTableSchemaName = quotedName(results
.getString("PKTABLE_SCHEM"));
final String pkTableName = quotedName(results
.getString("PKTABLE_NAME"));
final String pkColumnName = quotedName(results
.getString("PKCOLUMN_NAME"));
final String fkTableCatalogName = quotedName(results
.getString("FKTABLE_CAT"));
final String fkTableSchemaName = quotedName(results
.getString("FKTABLE_SCHEM"));
final String fkTableName = quotedName(results
.getString("FKTABLE_NAME"));
final String fkColumnName = quotedName(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;
}
if (isBlank(foreignKeyName))
{
foreignKeyName = MetaDataUtility.constructForeignKeyName(pkColumn,
fkColumn);
}
final Optional foreignKeyOptional = foreignKeys
.lookup(foreignKeyName);
final MutableForeignKey foreignKey;
if (foreignKeyOptional.isPresent())
{
foreignKey = foreignKeyOptional.get();
}
else
{
foreignKey = new MutableForeignKey(foreignKeyName);
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);
}
}
}
finally
{
results.close();
}
}
/**
* 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 SchemaReference schema = new SchemaReference(catalogName, schemaName);
final Optional tableOptional = catalog.lookupTable(schema,
tableName);
if (tableOptional.isPresent())
{
final Table table = tableOptional.get();
final Optional columnOptional = table
.lookupColumn(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 column reference for a column that is referenced by a foreign key, %s",
column.getFullName()));
}
return column;
}
private void retrieveForeignKeysUsingDatabaseMetadata(final NamedObjectList allTables)
throws SchemaCrawlerSQLException
{
final NamedObjectList foreignKeys = new NamedObjectList<>();
for (final MutableTable table: allTables)
{
if (table instanceof View)
{
continue;
}
final DatabaseMetaData metaData = getMetaData();
try (final MetadataResultSet results = new MetadataResultSet(metaData
.getImportedKeys(unquotedName(table.getSchema().getCatalogName()),
unquotedName(table.getSchema().getName()),
unquotedName(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(unquotedName(table.getSchema().getCatalogName()),
unquotedName(table.getSchema().getName()),
unquotedName(table.getName())));)
{
createForeignKeys(results, foreignKeys);
}
catch (final SQLException e)
{
throw new SchemaCrawlerSQLException("Could not retrieve foreign keys for table "
+ table, e);
}
}
}
private void retrieveForeignKeysUsingSql(final InformationSchemaViews informationSchemaViews)
throws SchemaCrawlerSQLException
{
final NamedObjectList foreignKeys = new NamedObjectList<>();
final Query fkSql = informationSchemaViews.getForeignKeysSql();
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);
}
}
}