query operation

• 查询操作

query operation的用法和样例：

例句

1. Some query operations must be expressed as a method call.
   某些查询操作必须表示为方法调用。
2. Probably the most common query operation is to apply a filter in the form of a Boolean expression.
   也许最常用的查询操作是应用布尔表达式形式的筛选器。