SQL3 generalizes the relational model into an object model offering abstract data types, multiple inheritance, and dynamic polymorphism. Tables may then contain collections (multisets) of objects, and sets and lists are defined as closely related collection types. By specifying an SQL_Table type template to correspond to the existing Table concept, it is possible to treat sets and lists as subtypes of tables that inherit the behavior (and SQL syntax) for tables, while adding their own specializations. The SQL set-at-a-time data manipulation language can then be applied to collections of objects, i.e. tables in which each row is an object.
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机译：SQL3将关系模型概括为提供抽象数据类型，多重继承和动态多态性的对象模型。然后，表可以包含对象的集合（Multisets），并且集合和列表定义为密切相关的收集类型。通过指定要对应于现有表概念的SQL_Table类型模板，可以将集合和列表视为继承表的表格（和SQL语法）的表的子类型，同时添加自己的专业化。然后，可以将SQL Set-AT-A-Time Data Manipulation语言应用于对象的集合，即，每行是对象的表。
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