Empty arrays should not be confused with NULL arrays or with arrays containing just NULL values.
不应将空阵列与NULL阵列或与只包含null值的阵列混为一谈。
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。
This new validation will enforce NOT null column constraints by rejecting null values, but only in situations where your database would reject a null value.
这种校验会通过拒绝空值，强迫加上非空[not NULL]字段的约束，但是也只有在这种情况下，你的数据库会拒绝空值。
Unfortunately, many designers have still not learnt that the special null pointer or null object is an equally bad idea.
遗憾的是，许多设计者并没有认识到空指针或空对象带来的危害。
But as we hope we've shown in the table, that really represents an array with a single element whose value is null, not a null array.
但是，正如我们希望的，在表中已经显示，它真正表示的是含有单一元素的数组，元素的值为“零”(null)，而不是一个“零”(null)数组。
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)。
Application of data to targets: Replication requires columns of like attributes (for example, INTEGER NOT NULL from the source table to INTEGER NOT NULL at the nickname).
到目标的数据应用：复制需要像属性一样的列(例如，从源表的INTEGERNOT NULL到别名上的INTEGER NOT NULL)。
Most statisticians would not argue if you decided to reject the null hypothesis that the results can be accounted for in terms of random sampling variability from the null distribution.
如果您决定排除虚假设—结果可以按照零分布的随机抽样可变性获得，那么大多数统计师都不会有争议。
By default, a column can contain a NULL value, but if you don't want that, you can append the "NOT NULL" postfix to the field definition.
默认情况下，列可以包含null值，但是，如果不想这样，可以在字段定义中附加“NOT NULL”后缀。
For example, if a before trigger supplies value to a NOT NULL column, then the before trigger is executed first and a value is supplied to the column so that the NOT NULL constraint isn't violated.
例如，如果一个BEFORE触发器给一个NOT null列提供值，那么先执行BEFORE触发器，给列提供值，所以不会违反NOT NULL约束。
The code in listing 11 first checks if the response passed is null, and, if not, then checks if the required fields are null.
清单11中的代码首先检查传递的响应是否为null，如果不是，则检查所需字段是否为null。
The default model binder also cannot assign a null value to a property that does not accept nulls. In particular, the model binder cannot assign a null value to the UnitsInStock property.
默认的模型绑定器同样不能指定一个null值到一个不允许为null的属性中，这里的情况是模型绑定其不能指定一个null值到UnitsInStock属性中。
A general, good practice is not to allow null (that is, no value) columns in a relational database, because when you attempt to read such a column, you get a null value exception.
通常，一种优秀的实践就是不要在关系数据库中使用null(即没有值)列，因为当您试图读取这类列时，您将得到一个null值异常。
Guaranty contract would be null and void not only because of its own factors but also because of being null and void of the principal contract.
担保合同既可因自身原因而无效，亦可因主合同无效而导致无效。
If a NOT NULL constraint is specified, then the column must have a default value other than NULL.
如果规定一个不允许有空值是一个约束，那么字段必须有一个不同于空值的默认值。
This will prevent passing NULL to columns that do not allow null values.
因为如果有默认值的话，可以避免给非空的column传递空值。
它可以为空不空。
You can attach unique constraints to columns that allow null values, whereas you can attach primary key constraints only to columns that do not allow null values.
可将唯一约束附加到允许空值的列，但是只能将主键约束附加到不允许空值的列。
Null values do not match other null values.
空值不与其他的空值匹配。
Suretyship contract would be null and void not only because of being null and void of the principal contract but also because of its own.
保证合同既可能因主合同无效而无效，亦可因自身的原因而无效。
Suretyship contract would be null and void not only because of being null and void of the principal contract but also because of its own.
仲裁协议除了应具备一般契约的有效要件外，还应具备其特别有效要件； 反之，可导致仲裁协议无效。
Guaranty contract would be null and void not only because of its own factors but also because of being null and void of the principal contract.
仲裁协议除了应具备一般契约的有效要件外，还应具备其特别有效要件；反之，可导致仲裁协议无效。
Suretyship contract would be null and void not only because of being null and void of the principal contract but also because of its own.
担保合同既可因自身原因而无效，亦可因主合同无效而导致无效。
Suretyship contract would be null and void not only because of being null and void of the principal contract but also because of its own.
担保合同既可因自身原因而无效，亦可因主合同无效而导致无效。
应用推荐