Can OpenJPA be used to reverse map a database view? - openjpa

Question

I have database views that have a column that uniquely identifies each row in the view. This column could be used as the primary key even though the view doesn't have a primary key in its definition (DDL) because it's a view.
OpenJPA is refusing to map the views to Java POJOs because there is no primary key.
I have a list of views and primary keys and I have a ReverseCustomizer. Is it possible I can give OpenJPA the column/field to be used as the primary key / id for each view / class?
Currently, the reverse mapping tool calls unmappedTable for each view and I'd like to tell the reverse mapper to do the mapping with the primary key I provide.

Answer 1

Here's something to help you get started.
public class MyDBReverseCustomizer implements ReverseCustomizer {
private ReverseMappingTool rmt;
#Override
public void setTool(ReverseMappingTool rmt) {
this.rmt = rmt;
}
#Override
public boolean unmappedTable(Table table) {
// this method is called to give this class an opportunity to map the
// table which would not be mapped otherwise. Returning false says
// the table wasn't mapped here.
//Class klass = rmt.generateClass(table.getIdentifier().getName(), null);
String packageName = rmt.getPackageName();
String tableName = table.getIdentifier().getName();
String className = NameConverters.convertTableName(tableName);
Class klass = rmt.generateClass(packageName+"."+className, null);
ClassMapping cls = rmt.newClassMapping(klass, table);
Column pk = null;
for ( Column column : table.getColumns() ) {
String columnName = column.getIdentifier().getName();
String fieldName = rmt.getFieldName(columnName, cls);
Class type = rmt.getFieldType(column, false);
FieldMapping field = cls.addDeclaredFieldMapping(fieldName, type);
field.setExplicit(true);
field.setColumns(new Column[]{column});
// TODO: set the appropriate strategy for non-primitive types.
field.setStrategy(new PrimitiveFieldStrategy(), null);
if ("MODEL_VIEW".equals(tableName) && "MODEL_ID".equals(columnName)) {
pk = column;
field.setPrimaryKey(true);
}
customize(field);
}
//cls.setPrimaryKeyColumns(new Column[]{pk});
cls.setObjectIdType(null, false);
cls.setIdentityType(ClassMapping.ID_DATASTORE);
cls.setStrategy(new FullClassStrategy(), null);
return true;
}
...
}