All columns returned by the recursive cte are nullable regardless of the nullability of the columns returned by the participating select statements 无论参与的select语句返回的列的为空性如何，递归cte返回的全部列都可以为空。
This setting only affects the nullability of new columns when the nullability of the column is not specified in the create table and alter table statements 仅当create table和alter table语句中没有指定列的为空性，此设置才能影响新列的为空性。
The data modified in the columns in the underlying table must adhere to the restrictions on those columns , such as nullability , constraints , default definitions and so on 在基础表的列中修改的数据必须符合对这些列的约束，例如为空性、约束及default定义等。
When you use create table or alter table , database and session settings influence and possibly override the nullability of the data type that is used in a column definition 使用create table或alter table时，数据库和会话设置会影响且可能代替列定义中所用的数据类型的为空性。
If null or not null is explicitly stated for each column , the temporary tables are created by using the same nullability for all connections that execute the stored procedure 如果为每个列显式声明了null或not null ，那么将对所有执行该存储过程的连接使用相同的为空性创建临时表。
The nullability property of arithmetic operators over the floating point data type is changed to nonnullable for the case where the inputs are nonnullable and ansi warnings is on 在输入不可为空并且ansi _ warnings为on的情况下，对浮点数据类型执行运算的算术运算符的为空性属性将更改为不可为空值。
The nullability of any column in the result set returned by except or intersect is the same as the nullability of the corresponding column that is returned by the query on the left side of the operand Except或intersect返回的结果集中的任何列的为空性与操作数左侧的查询返回的对应列的为空性相同。
We recommend that you always explicitly define noncomputed columns as null or not null or , if you use a user - defined data type , that you allow the column to use the default nullability of the data type 建议始终将非计算列显式定义为null或not null ；如果使用用户定义数据类型，则建议允许该列使用此数据类型的默认为空性。
When you create or alter a table with the create table or alter table statements , the database and session settings influence and possibly override the nullability of the data type that is used in a column definition 如果用create table或alter table语句创建或更改表，则数据库或会话设置将影响并且可能覆盖用于列定义的数据类型的为空性。
For a more reliable operation of transact - sql scripts that are used in databases with different nullability settings , it is better to always specify null or not null in create table and alter table statements 为使transact - sql脚本在包含不同为空性设置的数据库中获得更可靠的操作，最好始终在create table和alter table语句中指定null或not null 。
