Ansi_null_dflt_on statement in SQL Server

The SET ANSI_NULL_DFLT_ON statement in SQL Server is the counterpart of the ANSI_NULL_DFLT_OFF. It controls the default nullability of new columns created with create table or alter table statement. It set the default nullability of new columns or variables that are not explicitly defined as null or not null.

Setting	Implicit nullability
ANSI_NULL_DFTL_ON	Default to null
ANSI_NULL_DFTL_OFF	Default to not null

 The best practices are that we need to always explicitly define null or not null when we are creating a table or column.