确定锁定一个多表查询什么?。
介绍了在SQL中用聚合函数实现多表查询的一种方法。
This paper presents a method of query of tables by using aggregate function in SQL.
说明:ACCESS多表查询例程,数据库编程源码,很好的参考资料。
Routine ACCESS multi table query, database programming source code, a good reference.
文章从基于构件的领域软件开发入手,以在水信息领域中最普遍、最有代表性的信息查询中的多表查询模块为例,对其构件接口进行分析设计。
The article proceeds with software development of domain based on component, taking the inquiry module as the example, analyses and designs to its component interface.
另外,查询分解的XML数据很困难,常常需要多表联结。
Furthermore, querying decomposed XML data can be challenging, often requiring multi-table joins.
当表十分小且索引集群率(index -clustering ratio)十分低,或查询需要很多表行时,索引扫描的成本可能更高。
An index scan might be more costly when the table is small and the index-clustering ratio is low, or the query requires most of the table rows.
比方说,对于一般开发人员,使用SQL创建输出结果为新xml文档的多表外连接查询要比编写XQuery复杂得多。
For example, using SQL to create a multi-table outer join that outputs its results to a new XML document is much more complicated to the average developer than writing XQuery.
说明:ACCESS数据库多表关联查询例程,很好的参考资料,有需要的就下载吧。
Relational query multi table ACCESS database routines, a good reference, there is a need to download it.
在数据仓库环境下,经常会碰到涉及大量数据的复杂查询,包括多表连接、聚集计算等。
Under data warehouse environment, the complex query of the mass data are met frequently, including the multi-tables join, gathers the computation and so on.
联接查询是关系数据库中最主要的查询,本文通过实例说明关系数据库中进行多表联接查询时联接的顺序性。
The joint query is the mainly query in the relation database. This article showed the order of the joint query on multi-tables through the example.
本文分析和讨论了如何利用计算机编程进行“装配树”统计的问题,并介绍了利用数据库的多表联接查询方法进行快速统计的技巧。
The problem how to program the statistics of "assembly tree" on the computer is analyzed and discussed in the article. The an to compile quick statistics using multiple data presentation is described.
为了增强关系数据库中的关键字搜索查询结果,考虑了多表之间以及元组之间的语义关系,提出了一种语义评分函数。
In order to enhance the search results of keyword search in relational databases, semantic relationship among relations and tuples is employed and a semantic ranking function is proposed.
为了增强关系数据库中的关键字搜索查询结果,考虑了多表之间以及元组之间的语义关系,提出了一种语义评分函数。
In order to enhance the search results of keyword search in relational databases, semantic relationship among relations and tuples is employed and a semantic ranking function is proposed.
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