Does LINQ select return null?

Does LINQ select return null?

LINQ queries should never return null and you should not get an exception if the result is empty. You probably have an error in your code.

How do I insert a null check in LINQ?

Name == “Name”). ToList(); This will essentially resolve the Name property to null if MyOtherObject is null, which will fail the comparison with “Name” . You can just make your predicate check for null…

How do you handle null in LINQ query?

An object collection such as an IEnumerable can contain elements whose value is null. If a source collection is null or contains an element whose value is null , and your query doesn’t handle null values, a NullReferenceException will be thrown when you execute the query. var query1 = from c in categories where c !=

Is null in LINQ?

LINQ to SQL does not impose C# null or Visual Basic nothing comparison semantics on SQL. Comparison operators are syntactically translated to their SQL equivalents. The semantics reflect SQL semantics as defined by server or connection settings.

Can select return null?

The IS NULL condition is used in SQL to test for a NULL value. It returns TRUE if a NULL value is found, otherwise it returns FALSE. It can be used in a SELECT, INSERT, UPDATE, or DELETE statement.

How do I check if my IEnumerable is empty?

“check if ienumerable is empty c#” Code Answer

  1. IEnumerable enumerable = new List();
  2. if(! enumerable. Any())
  3. {
  4. throw new InvalidOperationException();
  5. }

Can IEnumerable be null?

The returned IEnumerable<> might be empty, but it will never be null .

How do you assign an empty string if the value is null in LINQ query?

var fields = from row in datarows from field in row from col in columnnames where field. Key == col select new { ColumnName = col, FieldValue = field. Value };

Can FirstOrDefault return null?

FirstOrDefault returns the default value of a type if no item matches the predicate. For reference types that is null . Thats the reason for the exception.

Does select return null if not found?

If your SQL query does not return any data there is not a field with a null value so neither ISNULL nor COALESCE will work as you want them to. By using a sub query, the top level query gets a field with a null value, and both ISNULL and COALESCE will work as you want/expect them to.

Is empty SQL query?

Is it better to return null or empty list?

Always. It is considered a best practice to NEVER return null when returning a collection or enumerable. ALWAYS return an empty enumerable/collection. It prevents the aforementioned nonsense, and prevents your car getting egged by co-workers and users of your classes.

How to check for null value in LINQ?

I am dealing with the LINQ queries, In which I have to diplay “N/A” were the value is null for the given property/column. You can use ternary operator as shwon in below example. Here MobileNo = “N/A” for the null values? MobileNo = (m.MobileNo == null)?

What is the difference between LINQ and SQL?

– no magic strings – intellisens support (which is great time saver) – compile check (if db is changed you are informed of outdated queries) – faster to develop and play with – lazy loading (which in some cases could perform better than pure SQL) – you have object model and not just raw information

How to handle Nulls in LINQ to entities?

If a source collection is null or contains an element whose value is null, and your query doesn’t handle null values, a NullReferenceException will be thrown when you execute the query. You can code defensively to avoid a null reference exception as shown in the following example:

How to select random records in LINQ?

To get random questions, you need to use the rand () in SQL SELECT random rows statement. Syntax1: Select All Column Random Rows. The above syntax select the random from all the columns of a table. Syntax2: Retrieve Random Rows From Selected Columns in Table.