LLBLGen 3.1, .NET 4, PostgreSQL 9

Hello,

I wanna create DB independent application, so I have created custom IConcurrencyPredicateFactory

    class OptimisticConcurrencyFactory : IConcurrencyPredicateFactory
    {
        public IPredicateExpression CreatePredicate(ConcurrencyPredicateType predicateTypeToCreate, object containingEntity)
        {
            IPredicateExpression toReturn = null;

            if (predicateTypeToCreate == ConcurrencyPredicateType.Save)
            {
                toReturn = new PredicateExpression();
                CommonEntityBase entity = (CommonEntityBase)containingEntity;
                EntityField2 concurrencyField = (EntityField2)entity.Fields["ConcurrencyGuid"];
                toReturn.Add(concurrencyField == concurrencyField.CurrentValue);
            }

            return toReturn;
        }
    }

and added in CommonEntityBase

        protected override IConcurrencyPredicateFactory CreateConcurrencyPredicateFactory()
        {
            return new CareSense.ORMEntities.DatabaseGeneric.HelperClasses.OptimisticConcurrencyFactory();
        }

I'm setting ConncurencyGuid field in Adapter before save

        public override bool SaveEntity(IEntity2 entityToSave, bool refetchAfterSave, IPredicateExpression updateRestriction, bool recurse)
        {
            AddConcurrencyGuidToEntity(entityToSave, recurse);

            return base.SaveEntity(entityToSave, refetchAfterSave, updateRestriction, recurse);
        }

        public override int SaveEntityCollection(IEntityCollection2 collectionToSave, bool refetchSavedEntitiesAfterSave, bool recurse)
        {
            foreach (IEntity2 entity in collectionToSave)
            {
                AddConcurrencyGuidToEntity(entity, recurse);
            }

            return base.SaveEntityCollection(collectionToSave, refetchSavedEntitiesAfterSave, recurse);
        }

        private void AddConcurrencyGuidToEntity(IEntity2 entityToSave, bool recurse)
        {
            if (recurse)
            {
                ObjectGraphUtils objectGraphUtils = new ObjectGraphUtils();

                System.Collections.Generic.List<IEntity2> entityList = objectGraphUtils.ProduceTopologyOrderedList(entityToSave);

                foreach (IEntity2 entity in entityList)
                {
                    if (entity.IsDirty)
                    {
                        entity.Fields["ConcurrencyGuid"].CurrentValue = System.Guid.NewGuid().ToString();
                    }
                }
            }
            else
            {
                if (entityToSave.IsDirty)
                {
                    entityToSave.Fields["ConcurrencyGuid"].CurrentValue = System.Guid.NewGuid().ToString();
                }
            }
        }

Everything is OK when I'm using SaveEntity method, but on SaveEntityCollecton ORMConcurrencyException is thrown every time.

Thanks in advance.

There are a couple of things I don't understand in your code:

Your concurrency predicate

if (predicateTypeToCreate == ConcurrencyPredicateType.Save)
            {
                toReturn = new PredicateExpression();
                CommonEntityBase entity = (CommonEntityBase)containingEntity;
                EntityField2 concurrencyField = (EntityField2)entity.Fields["ConcurrencyGuid"];
                toReturn.Add(concurrencyField == concurrencyField.CurrentValue);
            }

Based on all your code and the way you set the GUID to dirty entities, that predicate will be always true.

entity.Fields["ConcurrencyGuid"].CurrentValue = System.Guid.NewGuid().ToString();

About the exception, please post the exact message and stack trace.

I seems that

adapter.SaveEntity(...) 

first calls

SD.LLBLGen.Pro.ORMSupportClasses.EntityBase2.GetConcurrencyPredicate

and then

public override bool SaveEntity

but

adapter.SaveEntityCollection 

first calls

public override int SaveEntityCollection

and then

SD.LLBLGen.Pro.ORMSupportClasses.EntityBase2.GetConcurrencyPredicate

That's why adapter.SaveEntity(...) is working fine in my case.

But adapter.SaveEntityCollection(...) creates concurrency predicate after new ConcurrencyGuid is set, and, or course, concurrency check fails.

Is there any way to call

SD.LLBLGen.Pro.ORMSupportClasses.EntityBase2.GetConcurrencyPredicate

before

public override int SaveEntityCollection

SaveEntityCollection loops on the entities to call SaveEntity for each one. So the GetConcurrencyPredicate should be called before each SaveEntity.

I don't really see why the order in which calls are made make a difference as well. You shouldn't need to override SaveEntityCollection to use concurrencypredicatefactory, it's called automatically when it's inside an entity to produce a predicate.

Walaa wrote:

SaveEntityCollection loops on the entities to call SvaeEntity for each one. So the GetConcurrencyPredicate should be called before each SaveEntity.

I see. But it calls base.SaveEntity, not my override.

So here is my workaround, which also solves same issue with recurse save:

        public override bool SaveEntity(IEntity2 entityToSave, bool refetchAfterSave, IPredicateExpression updateRestriction, bool recurse)
        {
            if (recurse)
            {
                ObjectGraphUtils objectGraphUtils = new ObjectGraphUtils();

                System.Collections.Generic.List<IEntity2> entityList = objectGraphUtils.ProduceTopologyOrderedList(entityToSave);

                foreach (IEntity2 entity in entityList)
                {
                    base.SaveEntity(entity, refetchAfterSave, false);
                }

                return true;
            }
            else
            {
                AddConcurrencyGuidToEntity(entityToSave);
                return base.SaveEntity(entityToSave, refetchAfterSave, updateRestriction, false);
            }

        }

        public override int SaveEntityCollection(IEntityCollection2 collectionToSave, bool refetchSavedEntitiesAfterSave, bool recurse)
        {
            int counter = 0;
            foreach (IEntity2 entity in collectionToSave)
            {
                if (entity.IsDirty)
                {
                    this.SaveEntity(entity, refetchSavedEntitiesAfterSave, recurse);
                    counter++;
                }
            }

            return counter;
        }

        private void AddConcurrencyGuidToEntity(IEntity2 entityToSave)
        {
            if (entityToSave.IsDirty)
            {
                entityToSave.Fields["ConcurrencyGuid"].CurrentValue = System.Guid.NewGuid().ToString();
            }
        }