First off, Nullable<int> is just a shorthand for something like: struct Nullable<T> { bool hasValue; T value; } Plus all the constructors, accessors, and so on. That’s all it is — a nullable int is an ordinary int plus a flag that says whether the int is null or not. All the rest is compiler … Read more
There can be two answers. Firstly, this may be probably because your query is returning NULL and the model is not accepting null. Second fix may be, if you are using anonymous types, then try typecasting the query result into nullable type. e.g. Id = (int?) op.Id, how to find which property is returning NULL? … Read more
It’s just syntactic sugar. They will behave exactly the same way – the nullity test actually gets compiled into a call to HasValue anyway. Sample: public class Test { static void Main() { int? x = 0; bool y = x.HasValue; bool z = x != null; } } IL: .method private hidebysig static void … Read more
Other way: Where object.Equals(c.ParentId, categoryId) or Where (categoryId == null ? c.ParentId == null : c.ParentId == categoryId)
You can try this:- DateTime? dt = string.IsNullOrEmpty(date) ? (DateTime?)null : DateTime.Parse(date);
I agree with Stuart Marks that list == null ? Stream.empty() : list.stream() is the right way to do this (see his answer), or at least the right way to do this pre-Java 9 (see edit below), but I’ll leave this answer up to demonstrate usage of the Optional API. <T> Stream<T> getStream(List<T> list) { … Read more
According to the MSDN : Calling GetType on a Nullable type causes a boxing operation to be performed when the type is implicitly converted to Object. Therefore GetType always returns a Type object that represents the underlying type, not the Nullable type. When you box a nullable object, only the underlying type is boxed. Again, … Read more
You could use orElse(null): String o = getOptional().orElse(null); if (o == null) { return; }
Ah ha! I found an even more efficient solution than @Trebz’s! datePrm.Value = nullableDate ?? (object)DBNull.Value;
Better error messages and error handling, especially if you also add the JSR303 @NotNull annotation. If you create the column as NOT NULL but don’t tell JPA it’s not null, JPA will assume that null values are OK. When you try to save an object with nulls, it’ll proceed to send that to the DB … Read more