LLBLgen 3.5 Derived Tables Query

Question

I'm trying to get the following SQL to work with llblgen...

SELECT *,(SELECT TOP (1) Id FROM Content.Grades WHERE Account = Authentication.Account.Id ORDER BY Grades.GradingDate DESC) AS CurrentGrade FROM Authentication.Account WHERE (SELECT TOP (1) Grade FROM Content.Grades WHERE Account = Authentication.Account.Id ORDER BY Grades.GradingDate DESC) = 5


 var dtFields = new ResultsetFields(1);
            dtFields.DefineField(GradesFields.Id, 0);
            var dtDefinition = new DerivedTableDefinition(
                           dtFields, "c", new PredicateExpression(GradesFields.Grade == SelectedGrade.Value));

            // specify the relation which is a dynamic relation. 
            var relation = new DynamicRelation(dtDefinition, JoinHint.Inner,
                                            EntityType.GradesEntity, "o",
                                           (new EntityField2(AccountFields.Id.ToString(), "c", typeof(string)) ==
                                            GradesFields.Account.SetObjectAlias("o")));

            RelationBucket.Relations.Add(relation);

I'm struggling to get this to fit as everytime I try the query i'm getting errors on the field...

Answer 1

Ok I solved my own issue here.

When using a derived table we need to set an object alias on all references. This include the sort fields and predicate fields.

            var dtFields = new ResultsetFields(2);
            dtFields.DefineField(GradesFields.Account, 0);
            dtFields.DefineField(GradesFields.Grade, 1);
            var dtDefinition = new DerivedTableDefinition(
                           dtFields, "c", null, null,
                           new SortExpression(GradesFields.GradingDate | SortOperator.Descending), null, 1, false);

            // specify the relation which is a dynamic relation. 
            var relation = new DynamicRelation(dtDefinition, JoinHint.Inner,
                                            EntityType.AccountEntity, "o", (AccountFields.Id.SetObjectAlias("o") ==
                                            GradesFields.Account.SetObjectAlias("c")));

            repositoryQuery.Relations.Add(relation);
            repositoryQuery.PredicateExpression.Add(new EntityField2("Grade", "c", typeof(int)) == SelectedGrade.Value);

 AccountFields.Lastname.SetObjectAlias("o") | SortOperator.Ascending,