Published 16 November 2017
[NOT] NULL option is not specified in CREATE/DECLARE TABLE statement
A column definition has not specified that a column is NULL or NOT NULL.
Because the default of allowing NULLs can be changed with the database setting ‘ANSI_NULL_DFLT_ON’, you should explicitly define a column as NULL or NOT NULL for noncomputed columns or, if you use a user-defined data type, that you allow the column to use the default nullability of the data type. Sparse columns must always allow NULL.
NOTE: This issue is only shown once for each table definition.