01 2022 档案

QtConcurrent

摘要：The QtConcurrent namespace provides high-level APIs that make it possible to write multi-threaded programs without using low-level threading primitive 阅读全文

posted @ 2022-01-19 10:33 菜鸟_IceLee 阅读(487) 评论(0) 推荐(0) 编辑

6 ODB Relationships ODB依赖关系

摘要：6 Relationships 依赖关系 Relationships between persistent objects are expressed with pointers or containers of pointers. The ODB runtime library provides 阅读全文

posted @ 2022-01-14 14:11 菜鸟_IceLee 阅读(301) 评论(0) 推荐(0) 编辑

4 ODB Querying the Database ODB数据库查询

摘要：If we don't know the identifiers of the objects that we are looking for, we can use queries to search the database for objects matching certain criter 阅读全文

posted @ 2022-01-13 09:18 菜鸟_IceLee 阅读(512) 评论(0) 推荐(0) 编辑

11 ODB Session 会话

摘要：A session is an application's unit of work that may encompass several database transactions. In this version of ODB a session is just an object cache. 阅读全文

posted @ 2022-01-10 10:09 菜鸟_IceLee 阅读(122) 评论(0) 推荐(0) 编辑

10 ODB Views 视图

摘要：An ODB view is a C++ class or struct type that embodies a light-weight, read-only projection of one or more persistent objects or database tables or t 阅读全文

posted @ 2022-01-10 10:00 菜鸟_IceLee 阅读(198) 评论(0) 推荐(0) 编辑

9 ODB Sections

摘要：ODB sections are an optimization mechanism that allows us to partition data members of a persistent class into groups that can be separately loaded an 阅读全文

posted @ 2022-01-10 09:21 菜鸟_IceLee 阅读(110) 评论(0) 推荐(0) 编辑

8 ODB 继承（Inheritance）

摘要：In C++ inheritance can be used to achieve two different goals. We can employ inheritance to reuse common data and functionality in multiple classes. F 阅读全文

posted @ 2022-01-10 09:06 菜鸟_IceLee 阅读(142) 评论(0) 推荐(0) 编辑