This exception is thrown when you set the Value property of a SQL structure to null . To prevent throwing this exception, you should check the IsNull property of the structure before accessing the Value property. public sealed class SqlNullValueException : SqlTypeException { // Public Constructors public SqlNullValueException ( ); public SqlNullValueException ( string message ); public SqlNullValueException (string message , Exception e ); } HierarchySystem.Object System.Exception(System.Runtime.Serialization.ISerializable) System.SystemException SqlTypeException SqlNullValueException |