/**
* The contents of this file are subject to the license and copyright
* detailed in the LICENSE and NOTICE files at the root of the source
* tree and available online at
*
* http://www.dspace.org/license/
*/
package org.dspace.storage.rdbms.migration;
import java.io.IOException;
import java.sql.Connection;
import java.sql.SQLException;
import org.flywaydb.core.api.migration.MigrationChecksumProvider;
import org.flywaydb.core.api.migration.jdbc.JdbcMigration;
/**
* This class is in support of the DS-1582 Metadata for All Objects feature.
* It simply drops the database constraint associated with the "item_id" column
* of the "metadatavalue" table. This is necessary because to support DS-1582
* this column must be renamed to "resource_id".
* <P>
* This class was created because the names of database constraints differs based
* on the type of database (Postgres vs. Oracle vs. H2). As such, it becomes difficult
* to write simple SQL which will work for multiple database types (especially
* since unit tests require H2 and the syntax for H2 is different from either
* Oracle or Postgres).
* <P>
* NOTE: This migration class is very simple because it is meant to be used
* in conjuction with the corresponding SQL script:
* ./etc/migrations/[db-type]/V5.0_2014_09_26__DS-1582_Metadata_For_All_Objects.sql
* <P>
* Also note that this migration is dated as 2014_09_25 so that it will run
* just PRIOR to the corresponding SQL script listed above.
* <P>
* This class represents a Flyway DB Java Migration
* http://flywaydb.org/documentation/migration/java.html
*
* @author Tim Donohue
*/
public class V5_0_2014_09_25__DS_1582_Metadata_For_All_Objects_drop_constraint
implements JdbcMigration, MigrationChecksumProvider
{
/* The checksum to report for this migration (when successful) */
private int checksum = -1;
/**
* Actually migrate the existing database
* @param connection
* SQL Connection object
* @throws IOException
* A general class of exceptions produced by failed or interrupted I/O operations.
* @throws SQLException
* An exception that provides information on a database access error or other errors.
*/
@Override
public void migrate(Connection connection)
throws IOException, SQLException
{
// Drop the constraint associated with "item_id" column of "metadatavalue"
checksum = MigrationUtils.dropDBConstraint(connection, "metadatavalue", "item_id", "fkey");
}
/**
* Return the checksum to be associated with this Migration
* in the Flyway database table (schema_version).
* @return checksum as an Integer
*/
@Override
public Integer getChecksum()
{
return checksum;
}
}