private TranslatedQuery PrepareSubqueryParameters(SubQueryExpression subQueryExpression, out Parameter <Tuple> parameterOfTuple, out Type elementType, out ProjectionExpression projection)
{
// 1. Rewrite recordset and ItemProjector to parameter<tuple>
var subqueryTupleParameter = context.GetTupleParameter(subQueryExpression.OuterParameter);
var newDataSource = ApplyParameterToTupleParameterRewriter.Rewrite(
subQueryExpression.ProjectionExpression.ItemProjector.DataSource,
subqueryTupleParameter,
subQueryExpression.ApplyParameter);
var newItemProjectorBody = ApplyParameterToTupleParameterRewriter.Rewrite(
subQueryExpression.ProjectionExpression.ItemProjector.Item,
subqueryTupleParameter,
subQueryExpression.ApplyParameter);
var itemProjector = new ItemProjectorExpression(newItemProjectorBody, newDataSource, subQueryExpression.ProjectionExpression.ItemProjector.Context);
parameterOfTuple = context.GetTupleParameter(subQueryExpression.OuterParameter);
// 2. Add only parameter<tuple>. Tuple value will be assigned
// at the moment of materialization in SubQuery constructor
projection = new ProjectionExpression(
subQueryExpression.ProjectionExpression.Type,
itemProjector,
subQueryExpression.ProjectionExpression.TupleParameterBindings,
subQueryExpression.ProjectionExpression.ResultType);
// 3. Make translation
elementType = subQueryExpression.ProjectionExpression.ItemProjector.Item.Type;
var resultType = SequenceHelper.GetSequenceType(elementType);
var translateMethod = Translator.TranslateMethod.MakeGenericMethod(new[] { resultType });
return((TranslatedQuery)translateMethod.Invoke(context.Translator, new object[] { projection, tupleParameters.AddOne(parameterOfTuple) }));
}