This column should be NOT NULL, and will have no business meaning.
这个列应该是NOT NULL，并且没有商业意义。
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。
If defined as NOT NULL, the value corresponds to the start time associated with the most recent transaction (the value of the as ROW BEGIN column).
如果定义为NOT NULL，该值会对应于与最近的事务相关联的开始时间(ASROW begin列的值)。
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 above error can occur if the Sybase existing table definition declares one of the columns to be NOT NULL but there is no value for that column in one of the records of the result set.
如果sybase现有表定义声明某一列为NOT NULL，但是在结果集中的某一行记录在那一列没有值，就可能发生上述错误。
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。
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 NOT NULL attribute of column Credit_Line in table ACCOUNT has to be dropped because some other account types have been added that do not have a credit line.
ACCOUNT表中的 Credit_Line列的NOT NULL属性必须删除，这是因为添加了没有信用行的其他账号类型。
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。
The use of these specific columns ensures that the related column values are not inadvertently set to NULL.
这些特定列的使用能够确保相关的列值不会意外设置为NULL。
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。
For example, data classified as "unknown" usually indicates a column that is null or empty and probably not used.
例如，类别为“未知”的数据通常表明一个列只有null值或者为空，可能不被使用。
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。
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。
A workaround to this is to supply a default value to the not NULL column whose value comes from a BEFORE INSERT TRIGGER, so that the constraint is not violated.
一种解决方法是给从BEFORE INSERT触发器取得值的NOT null列提供默认值，这样就不会违反约束。
The itemNumber column provides a unique identity for each item (or row) and has an attached column-level constraint that enforces a valid value to always be supplied (NOT NULL).
itemNumber列提供了每个商品（或列）的惟一标识，它上面还有列级约束，强制要求提供正确的值（NOT NULL）。
For example, if you are creating a Customer table and the CustomerID is marked as not null, then when you define the primary key, CustomerID will show as a candidate column.
例如，如果您要创建一个Customer表并且CustomerID 被标记为not null，则当您定义主键时，CustomerID将会显示为备选列。
If this value is set to null or empty string, CLP throws a JCC exception: Column not updatable.
如果将这个值设置为null或空字符串，clp会抛出JCC异常：Column not updatable。
When you specify the element directive to retrieve element-centric XML, if the column has a NULL value, the corresponding element is not generated by the EXPLICIT mode.
当指定ELEMENT指令检索以元素为中心的XML时，如果列具有NULL值，则EXPLICIT模式将不生成相应的元素。
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。
The MAX function returns the highest value in a column. NULL values are not included in the calculation.
使用MAX函数可以将一列中的最大值返回出来。NULL值不包括在内。
"This behavior occurs because the primary key or the" not NULL "column of the database table was not selected in the data Form Wizard."
此行为的发生是由于在“数据窗体向导”中未选择数据库表的主键或“非null”列。
Changes to a column that does not allow NULL values when the table contains additional columns that are bound to the column that you are changing.
当表中的其他列绑定到要更改的列时，对不允许使用null值的列进行了更改。
Changes to a column that does not allow NULL values when the table contains additional columns that are bound to the column that you are changing.
当表中的其他列绑定到要更改的列时，对不允许使用null值的列进行了更改。
应用推荐