Restrictions and usage notes on DROP NOT NULL
DROPNOT NULL 的限制和使用说明
The uniqueness is ensured on the NOT NULL values.
确保NOT NULL 值的惟一性。
Constraints Supports, primary, foreign, unique, not null constraint.
约束支持主键、外键、惟一和非空约束。
We added the NOT NULL flag to indicate that the fields must not be null.
我们添加了NOT NULL标志来指示字段必须不能为空。
The portlet will automatically receive these parameters if they are not null.
如果这些参数不是空值，Portlet将自动接收它们。
If it is not null, the regular expression Pattern.matches " [0-9] + \ \. + [0-9] +".
如果不是null，那么规范的表达式Pattern.matches “ [0 - 9] + \ \ .”。
The first one asserts that the calculator instance object is not null, i.e. it exists.
第一个宣称这个计数器实例对象不是空，就像它实际存在一样。
The "name" column will be a CHAR (30), set to NOT NULL, and have a unique index on it.
“name”列的类型是CHAR(30)，不允许为空，而且根据此列建立了一个索引。
Partition compatibility is not affected by columns with not NULL or FOR BIT DATA definitions.
分区兼容性不受带有NOT NULL或FORBITDATA定义的列的影响。
Before using objects like rows and cells, be sure to test them to make sure they are not null.
在使用行和单元格这样的对象之前，一定要测试它们，确保它们不为空。
Similarly, the thread local password is checked and used if not null (and reset to null after use.)
类似地，仍将检查线程本地密码，如果不为空，则使用它(并且在使用后重新设置为空)。
If the input binding parameter is not NULL, then it means that the endpoint resides on a remote host.
如果输入绑定参数不是NULL，就意味着端点在远程主机上。
Notice in Listing 9 that the instance does have a valid (meaning it is not null) toAddress value.
注意在清单9 中，该实例确实有一个有效（意为非 nul ）的toAddress值。
The third TAB in the Twitter panel, following, first checks whether the following object is not null.
Twitter面板内的第三个选项卡是following，它先是检查following对象是否为null。
In lines 22 through 34 you select an operating system that is not NULL from the list obtained in previous step.
从第22行到第34行从上一步中获得的数组中选择一个不为空的操作系统。
For primary and unique keys, only the not null columns are listed and can be selected to define these keys.
对于主键和外键，只有非空列才能被列出和选择来定义这些键。
Initially, this routine checks if the passed inquiry context is not NULL and is for a group member inquiry.
这个例程首先检查传递的查询上下文是否非null，以及是否是用于组成员查询的上下文。
SQL USES a small integer which contains a zero if the column is not null or -1 if the column contains nulls.
如果列不包含空值，则SQL使用一个包含一个0的小整数；反之则包含- 1。
Some constraints will not change (not null, maximum length in the database), but some will vary with the country.
一些约束不会有变化（非空、数据库中的最大长度），但有一些会因国家而不同。
If the form input field is not null, set the payload you receive as the widget value, as shown in Listing 14.
如果表单输入字段不为空，将小部件的值设为接收到的负载，如清单14所示。
So in the example above, the NOT NULL constraint would get violated, and the INSERT statement would error out.
因此，在上面的示例中，会违反NOT NULL约束，INSERT语句会出错。
Usage: This parameter controls whether or not null data values are treated as zeros when used in calculations.
用法：该参数控制在计算中是否将null数据值看作0。
But in DB2, you must provide a value for NOT NULL columns in an INSERT statement when a default hasn't been defined.
但在DB 2中，如果未定义该值，则必须在insert语句中为NOT null列提供值。
Sometimes you may want to change this order or perhaps only specify values for columns that have NOT NULL constraints.
有时候您希望更改这种顺序或可能希望只为具有NOT NULL约束的列指定值。
Though you did not specify that column, the Rails migration created it for you anyway, with auto_increment and not NULL.
虽然没有指定这个列，但是Rails迁移会自动创建它，并具有auto_increment和NOT null属性。
These instance variables are not reset and, if they are not null, are used to provide the username and password on every request.
这些实例变量不能重新设置，如果它们不为空，则用于为每个请求提供用户名和密码。
When a unique index is created on a column in Oracle 10g, it ensures that the NOT NULL values entered in that column are unique.
当在Oracle10g中的列上创建UNIQUE索引时，会确保此列中输入的NOT null值是惟一的。
The unit test methods first verify that the object provided is not null, and then perform one or more very basic actions on the object.
单元测试方法首先验证所提供的对象不是空的，然后对该对象执行一个或多个非常基础的操作。
After a quick test of your new structure (namely, it's not NULL), continue to make the call using the call_usermodehelper_exec function.
快速测试新结构(即，非null)后，使用call_usermodehelper_exec函数继续调用。
After a quick test of your new structure (namely, it's not NULL), continue to make the call using the call_usermodehelper_exec function.
快速测试新结构(即，非null)后，使用call_usermodehelper_exec函数继续调用。
应用推荐