Package org.dspace.storage.rdbms.migration

Class MigrationUtils

java.lang.Object

org.dspace.storage.rdbms.migration.MigrationUtils

public class MigrationUtils
extends Object

This Utility class offers utility methods which may be of use to perform common Java database migration task(s) (via Flyway).

NOTE: This class specifically CANNOT utilize Hibernate, because it is used for database migrations which take place PRIOR to Hibernate loading. However, as you'll see below, all methods are protected to ensure the rest of the API cannot bypass Hibernate.

Author:

Tim Donohue

Method Summary

Modifier and Type	Method	Description
protected static Integer	dropDBConstraint(Connection connection, String tableName, String columnName, String constraintSuffix)	Drop a given Database Constraint (based on the current database type).
protected static Integer	dropDBSequence(Connection connection, String sequenceName)	Drop a given Database Sequence (based on the current database type).
protected static Integer	dropDBTable(Connection connection, String tableName)	Drop a given Database Table (based on the current database type).
protected static Integer	dropDBView(Connection connection, String viewName)	Drop a given Database View (based on the current database type).
static String	getResourceAsString(String resourcePath)	Read a given Resource, converting to a String.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

dropDBConstraint

protected static Integer dropDBConstraint(Connection connection,
 String tableName,
 String columnName,
 String constraintSuffix)
                                   throws SQLException

Drop a given Database Constraint (based on the current database type). Returns a "checksum" for this migration which can be used as part of a Flyway Java migration

Parameters:

connection - the current Database connection

tableName - the name of the table the constraint applies to

columnName - the name of the column the constraint applies to

constraintSuffix - Only used for PostgreSQL, whose constraint naming convention depends on a suffix (key, fkey, etc)

Returns:

migration checksum as an Integer

Throws:

SQLException - if a database error occurs

dropDBTable

protected static Integer dropDBTable(Connection connection,
 String tableName)
                              throws SQLException

Drop a given Database Table (based on the current database type). Returns a "checksum" for this migration which can be used as part of a Flyway Java migration

NOTE: Ideally, if you need to do a DROP TABLE, you should just create a Flyway SQL migration. This method should ONLY be used if the table name needs to be dynamically determined via Java.

Parameters:

connection - the current Database connection

tableName - the name of the table to drop

Returns:

migration checksum as an Integer

Throws:

SQLException - if a database error occurs

dropDBSequence

protected static Integer dropDBSequence(Connection connection,
 String sequenceName)
                                 throws SQLException

Drop a given Database Sequence (based on the current database type). Returns a "checksum" for this migration which can be used as part of a Flyway Java migration

NOTE: Ideally, if you need to do a DROP SEQUENCE, you should just create a Flyway SQL migration. This method should ONLY be used if the sequence name needs to be dynamically determined via Java.

Parameters:

connection - the current Database connection

sequenceName - the name of the sequence to drop

Returns:

migration checksum as an Integer

Throws:

SQLException - if a database error occurs

dropDBView

protected static Integer dropDBView(Connection connection,
 String viewName)
                             throws SQLException

Drop a given Database View (based on the current database type). Returns a "checksum" for this migration which can be used as part of a Flyway Java migration

NOTE: Ideally, if you need to do a DROP VIEW, you should just create a Flyway SQL migration. This method should ONLY be used if the view name needs to be dynamically determined via Java.

Parameters:

connection - the current Database connection

viewName - the name of the view to drop

Returns:

migration checksum as an Integer

Throws:

SQLException - if a database error occurs

getResourceAsString

public static String getResourceAsString(String resourcePath)

Read a given Resource, converting to a String. This is used by several Java-based migrations to read a SQL migration into a string, so that it can be executed under specific scenarios.

Parameters:

resourcePath - relative path of resource to read

Returns:

String contents of Resource