...
- If the EO is a fault, calling the EOUtilities method will cause the fault to be resolved, possibly requiring a trip to the db, even though pk info is already present in the fault and the trip to the db is really unneccesary at this point.
- If the EO has just been inserted and not yet committed, it does not have a pk yet, and the EOUtilities code will throw an exception. And it's not a logical exception corresponding to "no pk yet", but rather some uncaught exception thrown by some surprised Apple code.
Assigning Primary Keys
Wiki Markup
But sometimes you want to assign a permanent pk as soon as you create the EOEnterpriseObject, not wait until it's actually committed to the db. Here's some code to do that, which, in a given situation, will generate the pk in the same way that EOF would have generated it later, but do it right away. \ [WO:Thanks to Pierre Barnard\]
| Code Block |
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public void _insertObjectWithGlobalID(EOEnterpriseObject eo, EOGlobalID globalID)
{
EOEntity entity = EOUtilities.entityNamed(this, eo.entityName());
EODatabaseContext dbContext = EOUtilities.databaseContextForModelNamed(this, entity.model().name());
NSDictionary pkDict = primaryKeyDictionaryForDatabaseContextAndEntity(dbContext, entity);
if (pkDict == null || pkDict.count() != 1)
{
NSLog.err.appendln("Failed to generate primary key for entity " + entity.name() + ", or pk is compound.");
} else
{
Object pk = pkDict.allValues().lastObject();
globalID = EOKeyGlobalID.globalIDWithEntityName(entity.name(), new Object[] { pk });
}
super._insertObjectWithGlobalID(eo, globalID);
}
public static NSDictionary primaryKeyDictionaryForDatabaseContextAndEntity(EODatabaseContext dbContext, EOEntity entity) {
NSDictionary pk = null;
try {
dbContext.lock();
EOAdaptorChannel adaptorChannel = dbContext.availableChannel().adaptorChannel();
if (!adaptorChannel.isOpen()) {
adaptorChannel.openChannel();
}
pk = (NSDictionary) adaptorChannel.primaryKeysForNewRowsWithEntity(1, entity).lastObject();
}
catch (Exception e) {
NSLog.err.appendln("Can't get primary keys for entity " + entity.name() + " " + e);
}
finally {
dbContext.unlock();
return pk;
}
}
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