column constraint
英 [ˈkɒləm kənˈstreɪnt]
美 [ˈkɑːləm kənˈstreɪnt]
网络 约束又分为列约束; 列约束; 栏限制
双语例句
- Most implementations of JAXP include a line number and sometimes a column number to help you know exactly which part of the XML offended the constraint model.
JAXP的多数实现都包括行号，有时候还有列号，帮助定位违反约束模型的位置。 - You probably understand what is meant by a column definition, but you might not understand the idea of a constraint.
您可能理解列定义的含义，但是可能不理解约束的意义。 - The code in Listing 2 adds the column privacy constraint under the design and normalization category as batch mode with a severity of warning, as shown in Figure 23.
清单2中的代码在designandnormalization目录下以batch模式添加一个带有严重性警告的columnprivacy约束，如图20所示。 - This can take the form of adding a column, changing the data type for a column, adding a constraint, or even deleting a column.
这可以采用添加列、更改列的数据类型、添加约束或者甚至删除列的方式来实现。 - 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BEFOREINSERT触发器取得值的NOTNULL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（NOTNULL）。 - In this syntax example, you must either define a new column or define a new table-level constraint.
在这个语法示例中，必须定义一个新列或者定义一个表级约束。 - In SimpleRDB, primary and foreign keys are defined as a column associated to a key constraint that refers this column, with a table owning both columns and constraints.
在SimpleRDB中，主键和外键被定义为一个和指向该列的键值限制相关联的列，以及一个同时拥有列和限制的表。 - In this activity, you add documentation to every element in the model, including every column, every table, every constraint, and every trigger.
在这种情况中，你把文档添加到模型的每一个元素中，包括每个列，每个表，每个约束和每个触发器。 - 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NOTNULL列提供值，那么先执行BEFORE触发器，给列提供值，所以不会违反NOTNULL约束。 - Sparse columns are also going to be slower than a normal column, so consider avoiding them in performance sensitive queries where CPU, rather than I/ O, is the bounding constraint.
Sparse列的另一个特点就是会比普通的列要慢，所以，对于那些对CPU性能敏感胜过I/O的查询，应该考虑避免使用Sparse列，这是一个判断是否使用Sparse列的边界条件。 - If the column does participate in a check constraint, the database server will reject your modification when you try to save your work.
如果该列参与了check约束，则当您试图保存工作结果时，数据库服务器将拒绝您所做的修改。 - To delete a column that participates in a check constraint, you must first modify or remove the check constraint before you can delete the column.
若要删除参与check约束的列，在删除该列之前，必须首先修改或移除check约束。 - Newly added not nullable column ( s) are involved in the primary key or unique index ( constraint).
新添加的不可空列包含在主键或唯一索引（约束）中。 - Changing Column Vector of Constraint Matrix to decrease fixed Values of Objective Function
使线性规划目标函数减少预定值的研究 - If the weight limit for each column does not satisfy this constraint, an iterative exchange algorithm can guarantee the columns are not overweight in the case the level of center of gravity increase little.
如果每列限重这个约束不满足，设计了一种迭代交换算法，可以保证引起水平重心增加最小的情况下，各列均不超重。