Insert null value in whole column

Question

Through the front end, I want to insert a NULL value into a column whose DataType is Int.

I used like this:

POP.JobOrderID = Convert.ToInt32(DBNull.Value); 

But I can’t insert a Null value, it throws an error such as "Object cannot be cast from DBNull to other types":

How to insert null values?

Answer 1

if you want to do this POP.JobOrderID must be an int? type int? ( nullable int) not int

Answer 2

kleinohad is right. In addition, you should assign null , not DBNull.Value

Answer 3

Use Nullable<Int32> or just an alias: int? .

 POP.JobOrderID = 5; // or POP.JobOrderID = null; 

Usage in ADO.NET:

 command.Parameters.AddWithValue("@JobOrderId", POP.JobOrderID ?? DBNull.Value); 

which is equal to:

 POP.JobOrderID.HasValue ? POP.JobOrderID.Value : DBNull.Value; 

Answer 4

it

  POP.JobOrderID = new Nullable<Int32>(); 

should also work if JobOrderID is a type with a null value ( int? ).

Greetings

Answer 5

Like this:

  POP.JobOrderID = null; // JobOrderID should be of type int? which is a nullable-int 

Hope this helps.