How to insert null value in numeric column of Sql table using insert querry in C#.net(Window appl)

Yes i have marked it as null
But i want 2 insert null value in numeric column table when it has blank value or null value.
Thnk u for reply
 

A small question have you designed you column as accept null for that field. If so insert as

INSERT INTO "table_name" ("column1", "column2", ...)
VALUES ("value1", "value2", NULL,...)