Shaping Entity Framework Results

In order to comply with an interface I needed to write code similar to the following:
<br />return (from ActionRule ar in db.ActionRuleSet.Include("ConditionExpression")<br /> select new ActionRuleDataDTO() <br /> { <br /> Expresions = (from ConditionExpression ce in ar.ConditionExpression<br /> select new RuleExpressionDTO()<br /> {<br /> Type = ce.Operator,<br /> BoolOperator = ce.NextExpressionOperator<br /> }).ToArray() <br /> }).ToArray(); <br /> Which results in:
LINQ to Entities does not recognize the method 'EhrAdmin.Services.MSSQL.DTO.RuleExpressionDTO[] ToArray[RuleExpressionDTO](System.Collections.Generic.IEnumerable`1[EhrAdmin.Services.MSSQL.DTO.RuleExpressionDTO])' method, and this method cannot be translated into a store expression.
I'll revisit this when i get a chance but the fix at the moment is to convert ObjectQuery<actionrule> to List<actionrule> using the ToList() method.