DevForce Community Forum : Sql Where Clause

Sql Where Clause : You could eitheradd an "if"...

Mon, 12 Nov 2007 10:05:03 -700

Author: eileenv
Subject: 518
Posted: 12-Nov-2007 at 10:05am

You could either add an "if" clause in the event handler for every applicable entity or create a base class in which every applicable entity derives from and check for the base class in the handler.

Sql Where Clause : Would I put this with each entity...

Mon, 12 Nov 2007 07:16:44 -700

Author: orcities
Subject: 518
Posted: 12-Nov-2007 at 7:16am

Would I put this with each entity class that is needed?

Sql Where Clause : The "SQL Where Clause"...

Wed, 07 Nov 2007 12:40:13 -700

Author: eileenv
Subject: 518
Posted: 07-Nov-2007 at 12:40pm

The "SQL Where Clause" works great if the value of the filter column is invariant. It is not good if the value of the filter column can change -- as in the case with an "InActive" or "Deleted" column.

The more dynamic approach would be to add a "Fetching" handler to the PersistenceManager and add the clause if necessary. The Fetching event is raised just before the PersistenceManager sends a query to the server; the query is included in the event args for the Fetching handler, and you can modify it before DevForce applies it.

You might initialize your PersistenceManager as follows:

private void InitializePm() {

mManager = PersistenceManager.DefaultManager;

// other stuff

mManager.Fetching += new EventHandler(mManager_Fetching);

}

static void mManager_Fetching(object sender, EntityFetchingEventArgs e) {

IdeaBlade.Persistence.EntityQuery q = e.Query as EntityQuery;

if ( q.EntityType == typeof(Contact) ) {

q.AddClause("InActive", EntityQueryOp.EQ, 0);

}

Hope this helps.

Edited by eileenv - 07-Nov-2007 at 3:27pm

Sql Where Clause : Have you tried changing your query...

Thu, 01 Nov 2007 12:40:49 -700

Author: Linguinut
Subject: 518
Posted: 01-Nov-2007 at 12:40pm

Have you tried changing your query strategy to CacheOnly?

Sql Where Clause : Originally posted by eileenv Can...

Thu, 01 Nov 2007 07:17:00 -700

Author: orcities
Subject: 518
Posted: 01-Nov-2007 at 7:17am

Originally posted by eileenv

Can you provide a code snippet of the SQLWhereClause and the query you are trying to execute?

SQL Where Clause in Object Mapper: InActive = 0

Snippet:

RdbQuery query = new RdbQuery(typeof(Contact), ContactIdEntityColumn, EntityQueryOp.EQ, CurrentContact.ContactId);

query.AddClause(Contact.InActiveEnitityColumn, EntityQueryOp.EQ, 1);

Contact aContact = MainPm.EntityManager.GetEntity(query);

not copied and pasted. just an example

Sql Where Clause : Is this for a lot of tables or...

Wed, 31 Oct 2007 17:32:42 -700

Author: TrevLeyb
Subject: 518
Posted: 31-Oct-2007 at 5:32pm

Is this for a lot of tables or a single table?

I have managed this in two ways in the past. (based on the fact that the SQL where clause is defined in the definition of the table, and like you, not seeing how I could override that at runtime).

1. Create a second instance of the table in the Object Mapper which is identical but without the where clause. So, if it was for Customers, my main class would be 'Customers' whcih would include the where clause, and then have 'CustomersInclDeleted' as a object which did not. In that very special case where I need the deleted customers as well, I can use the second object.

2. The main way I manage this is to separate out the code that returns entities and entity sets behind a Facade layer. So I never directly call something like pm.GetEntities() in my code. I will always call a separate method in a Facade layer to do this, such as GetCustomers();

So in this case, I will have possibly either GetCustomers() and GetCustomersInclDeleted() methods in my Facade layer, or I will have a GetCustomers() and GetCustomers(bool inclDeleted) method.

Hope this helps.

Sql Where Clause : Can you provide a code snippet...

Wed, 31 Oct 2007 15:51:25 -700

Author: eileenv
Subject: 518
Posted: 31-Oct-2007 at 3:51pm

Can you provide a code snippet of the SQLWhereClause and the query you are trying to execute?

Sql Where Clause : After setting the Entity Where...

Tue, 23 Oct 2007 10:01:07 -700

Author: orcities
Subject: 518
Posted: 23-Oct-2007 at 10:01am

After setting the Entity Where clause is there a way to override it?

99% of the time I only need an entity with a specific flag set, not deleted. But, when someone tries to add a new entity I want to verify that it's not one that has been marked deleted.

When running an Rdb query it will never return a result even if I explicitly set the AddClause to the oposite value.