internal virtual DbExpression OfType(TypeUsage type)
{
// s.OfType<T> is normally translated to s.Filter(e => e is T).Project(e => e as T)
DbExpressionBinding rootBinding = _root.BindAs(_aliasGenerator.Next());
DbExpression filter = this.Filter(rootBinding.Filter(rootBinding.Variable.IsOf(type)));
OrderByLifterBase filterLifter = GetLifter(filter, _aliasGenerator);
DbExpressionBinding filterBinding = filter.BindAs(_aliasGenerator.Next());
DbExpression project = filterLifter.Project(filterBinding.Project(filterBinding.Variable.TreatAs(type)));
return(project);
}
private OrderByLifterBase GetLifter(DbExpression root)
{
return(OrderByLifterBase.GetLifter(root, _aliasGenerator));
}
internal DbExpression Limit(DbExpression argument, DbExpression limit)
{
OrderByLifterBase lifter = GetLifter(argument);
return(lifter.Limit(limit));
}
internal DbExpression Skip(DbExpressionBinding input, DbExpression skipCount)
{
OrderByLifterBase lifter = GetLifter(input.Expression);
return(lifter.Skip(skipCount));
}
internal DbExpression OfType(DbExpression argument, TypeUsage type)
{
OrderByLifterBase lifter = GetLifter(argument);
return(lifter.OfType(type));
}
internal DbExpression Filter(DbExpressionBinding input, DbExpression predicate)
{
OrderByLifterBase lifter = GetLifter(input.Expression);
return(lifter.Filter(input.Filter(predicate)));
}
internal DbExpression Project(DbExpressionBinding input, DbExpression projection)
{
OrderByLifterBase lifter = GetLifter(input.Expression);
return(lifter.Project(input.Project(projection)));
}
