Question

I am new to LLBLGen Pro and am checking for duplicate, I have the following SQL:

SQL:

select a.TopicId,atc.TopicCategoryId,a.Headline
from article a
inner join ArticleTopicCategory atc on atc.ArticleId = a.Id
where a.TopicId =  C0064FAE-093B-466E-8745-230534867D2F 
and a.Headline =  Test 
and atc.TopicCategoryId in ( 004D64F7-474C-48F9-9887-17B1E7532A84 )

Whenever I step though my function, it always returns 0:

LLBLGen Code:

public bool CheckDuplicateArticle(Guid topicId, List<Guid> categories, string headline)
        {
            ArticleCollection articles = new ArticleCollection();
            PredicateExpression filter = new PredicateExpression();
            RelationCollection relation = new RelationCollection();
            relation.Add(ArticleEntity.Relations.ArticleTopicCategoryEntityUsingArticleId);
            filter.AddWithAnd(ArticleFields.TopicId == topicId);
            filter.AddWithAnd(ArticleTopicCategoryFields.Id == categories);
            filter.AddWithAnd(ArticleFields.Headline == headline);
            articles.GetMulti(filter, 0, null, relation);
            return articles.Count > 0;
        }

Any help would be appreciated!

Answer 1

Not enough info to be sure this is helpful, but:

I would start by verifying that the SQL generated is what you expect. Do this with SQL Profiler, or if you don t have access turn on tracing in LLBLGen: LLBL Help Link.
I don t think that syntax for a category filter will work. I think if you want to include multiple categories using the simple predicate syntax you are using (field == value), you need to pass an array of Guids, and not a generic list. I don t think generic lists work, and I m surprised that it doesn t throw an exception. A quick thing to try would be "ArticleTopicCategoryFields.Id == categories.ToArray(). (Also, are they actual Guids, or strings made from Guids?)
Finally, if efficiency is at all an issue, you should look at using LLBL s GetScalar() functionality, so they you are just doing a simple, single-field query that returns a scalar value, and not projecting the full resultset onto an EntityCollection. Unfortunately I can t find a good link to this in the docs.

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