Contents
Why NULL checks are bad?
You can have an entire programming language without NULL. The problem with NULL is that it is a non-value value, a sentinel, a special case that was lumped in with everything else. Instead, we need an entity that contains information about (1) whether it contains a value and (2) the contained value, if it exists.
Why should NULLs in a relationship be avoided as far as possible?
Ans: NULL value means that no entry has been made into the column. They should be avoided to avoid the complexity in select & update queries and also because columns which have constraints like primary or foreign key constraints cannot contain a NULL value.
What does it mean to allow NULL?
It indicates data that does not exist. This is different to data that is blank. When you create a table in MySQL, it allows you to specify whether your fields are allowed to be NULL . If you specify “Allow Null”, then it will be possible to create records with NULL values in those fields.
What should one check for null if he does not?
Think of a search results on Stack Exchange in different groups (users, comments, questions). The method could check for null and abort the processing of users (which due to a bug is null) but return the “comments” and “questions” sections. The page would continue working except that the “users” section will be missing (which is a bug).
What are the advantages and disadvantages of null?
Disadvantages: The client have to check for null which is easily forgotten becaus the type system does not enforce this check. This might lead to hard-to-debug NullReferenceExceptions down the line. Not recommended. Throw an exception if the object is not found. Advantages: Simple and safe.
Is it better to return NULL or empty object?
It returns null if the LINQ query returns an empty result set. Is this “correct”. Is it better to return an empty object? If so then how can I do that?
How to check for Nulls in.net code?
Checking for nulls doesn’t imply conditional statements. If you worry that null checking makes your code less readable, then you may want to consider .NET code contracts. Consider installing ReSharper (or similar) to search your code for missing null reference checks