查询

Second, we rewrite the simple path expression into SQL statements. We research the different rewriting techniques for the different mapping nodes and different condition in where clause. For the query optimizing, we propose the path index based on the notion of node equivalence which is computed by bi-simulation algorithm.

第二步把简单路径表达式通过DTD字典重写为SQL语句，主要研究了对于SPE上的结点由于其映射的结点类型不同而进行不同的重写处理，同时研究了对于带有条件的查询在各种情况下的重写过程（如返回路径和条件路径不在一条路径上、多条件查询等）。

The optimization methods of database SQL query were studied and some available query optimization Methods were given out as follows: The incompatible data type should avoid to be used; More redundancy search parameters should be given as join condition in join query; In some condition, the number of note hitted to target was estimated by optimizing implement using the average density; Some other maths operating symbol should avoid to be used as condition parameters in WHERE clause; Some operating symbol and its sentence should avoid to be used also; When the cluster function was used,the WHERE clause should be paied attention to more,and so on.

作者单位：（重庆工学院商贸信息学院，重庆 400050）摘要：数据库SQL查询语句的优化，须注意：避免使用不兼容数据类型；连接查询中应多给连接条件提供一些冗余的搜索参数；某种条件下优化器只能使用其平均密度以估计命中的记录数；避免对WHERE子句中条件参数使用其它数学操作符；避免使用某些操作符及相应语句；聚簇函数的使用应注意WHERE子句。

In DAS model,one important problem faced is how to improve the query efficiency in the encryption database,and cryptograph index technology is one of the methods to improve cryptograph query efficiency in database.

DAS模型下，如何提高密文数据库的查询效率是当前面临的一个主要问题，而密文索引技术是提高数据库中密文查询效率的手段之一。

Web service is used for user interface which is to respond the user query, and also it call the indexed database that was already done to return the query result.

而Web Service则是用于用户交互的网络服务，负责响应用户的查询请求，并调用已经建立好的索引数据库返回查询结果。

But different search engine has different database, different search interface and different rules for searching.

但是不同的搜索引擎具有不同的数据库、查询界面和查询法则。

We have seen that descending into a query provides us with another query.

我们已经看到，下降到一个查询里给我们提供了另外一个查询。

L Record query: discharger can contain 8 times discharge data (each time 10 hours); users can inquire according to needs.

l 记录查询：放电仪可以存储8次放电数据（每次10小时），用户可以根据需要进行查询。

Select the Database of State Essential Druggery.

在本网站数据库栏目中选择"多库融合检索平台"并点击"进入"，在多库融合检索平台界面中的查询框中（如下图中红色圆圈所指处）键入待查询的信息，并在其中的数据库表中选择国家基本药物数据库，点击列表框右下角的"提交"按钮

On the home page of the Database of State Essential Druggery, type your search terms enter the query box. Select the field name to limit the search term, and then select Boolean operator to add multiple search terms. After than click the search button.

在本网站数据库栏目中选择"国家基本药物数据库"并点击"进入"至国家基本药物数据库单表检索界面，在其查询框中输入待检索的内容，选择相应的字段和逻辑关系（and ，or， not）来组织查询语句，然后点击"检索"按钮。

The method is evaluated on the Encarta encyclopedia, and shows that it provides more accurate and shorter answers than traditional document retrieval for queries.

该方法结合文本内容和结构信息，为XML文件设计了增强的索引结构，同时，改进了传统的排序方法和检索方案，提高了查询的精度和查询结果的合理性。

Since historical times,England ,where the early inhabitants were Celts, has been conquered three times .

从有历史以来，英国，在此地早期居住的是凯尔特人，已经被征服了三次。

Bluetooth OBEX File Transfer Enables the sending and receiving of files on your phone via Bluetooth.

蓝牙OBEX文件移动允许经过蓝牙传送和接受文件。。。。