V5_0_2014_09_25__DS_1582_Metadata_For_All_Objects_drop_constraint (DSpace Kernel :: API and Implementation 7.1.1 API)

java.lang.Object
- org.flywaydb.core.api.migration.BaseJavaMigration
- - org.dspace.storage.rdbms.migration.V5_0_2014_09_25__DS_1582_Metadata_For_All_Objects_drop_constraint

All Implemented Interfaces:

org.flywaydb.core.api.migration.JavaMigration
```
public class V5_0_2014_09_25__DS_1582_Metadata_For_All_Objects_drop_constraint
extends org.flywaydb.core.api.migration.BaseJavaMigration
```
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".
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).
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
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.
This class represents a Flyway DB Java Migration http://flywaydb.org/documentation/migration/java.html

Author:

Tim Donohue

Constructor Summary

Constructors
Constructor Description

V5_0_2014_09_25__DS_1582_Metadata_For_All_Objects_drop_constraint()

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`Integer`	`getChecksum()`	Return the checksum to be associated with this Migration in the Flyway database table (schema_version).
`void`	`migrate(org.flywaydb.core.api.migration.Context context)`	Actually migrate the existing database

Methods inherited from class org.flywaydb.core.api.migration.BaseJavaMigration
canExecuteInTransaction, getDescription, getVersion, isUndo

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - V5_0_2014_09_25__DS_1582_Metadata_For_All_Objects_drop_constraint
```
public V5_0_2014_09_25__DS_1582_Metadata_For_All_Objects_drop_constraint()
```
- Method Detail
  - migrate
```
public void migrate(org.flywaydb.core.api.migration.Context context)
             throws IOException,
                    SQLException
```
    Actually migrate the existing database
    
    Parameters:
    
    context - Flyway Migration Context
    
    Throws:
    
    IOException - A general class of exceptions produced by failed or interrupted I/O operations.
    
    SQLException - An exception that provides information on a database access error or other errors.
  - getChecksum
```
public Integer getChecksum()
```
    Return the checksum to be associated with this Migration in the Flyway database table (schema_version).
    
    Specified by:
    
    getChecksum in interface org.flywaydb.core.api.migration.JavaMigration
    
    Overrides:
    
    getChecksum in class org.flywaydb.core.api.migration.BaseJavaMigration
    
    Returns:
    
    checksum as an Integer