助手标题  
全文文献 工具书 数字 学术定义 翻译助手 学术趋势 更多
查询帮助
意见反馈
   from子句 的翻译结果: 查询用时:0.53秒
图标索引 在分类学科中查询
所有学科
计算机软件及计算机应用
更多类别查询

图标索引 历史查询
 

from子句
相关语句
  相似匹配句对
     is empty clause.
     代表空子句
短句来源
     Section 3 consists of formulas and clauses.
     第三节是公式和子句
短句来源
查询“from子句”译词为用户自定义的双语例句

    我想查看译文中含有:的双语例句
例句
为了更好的帮助您理解掌握查询词或其译词在地道英语中的实际用法,我们为您准备了出自英文原文的大量英语例句,供您参考。
  from clause
By restructuring the FROM clause via a subquery, SQL/Spatial is well adapted to the general spatial analysis procedure by using current GIS packages, while conforming well to the SQL design concepts.
      
A stream in the From clause may be followed by an optional sliding window specification, enclosed in brackets, and an optional sampling clause.
      
Assertions over any number of tables, and derived tables in the from clause of select statements are important SQL features for the patterns.
      
At the top of the from subtree a Join node connects the from clause with the subtree for the where clause.
      
Extract information regarding every variable declared in the FROM clause.
      
更多          


This paper introduces the significance and the implementation procedures and methods of the outer joint query, and emphatically points out that in the case of making the outer joint query for several tables with one father and several kids by using SQL, must pay attention to the precedence relationship of the joint targets and the joint conditions in FROM clauses, when there are several records fitting in with the joint conditions in the subtables, don't use the SUM () functions and GROUP BY clauses in SELECT—...

This paper introduces the significance and the implementation procedures and methods of the outer joint query, and emphatically points out that in the case of making the outer joint query for several tables with one father and several kids by using SQL, must pay attention to the precedence relationship of the joint targets and the joint conditions in FROM clauses, when there are several records fitting in with the joint conditions in the subtables, don't use the SUM () functions and GROUP BY clauses in SELECT— SQL statement to implement the group summary, and should make joint again after the summary has been implemented, otherwise it will cause the mistakes of the summary data, and increase the execution time greatly, and should make replacement in the case of making mathematic calculation for the fields with the mid- value of NULL.

介绍了外连接查询的意义、外连接查询的实现步骤和方法,着重指出:SQL对一父多子的多个表进行外连接查询时,要特别注意FROM子句中连接对象和连接条件的先后位置。当子表中符合连接条件的记录有多条时,不要在SQL—SELECT语句中用SUM()函数和GROUPBY子句实现分组汇总,应汇总后再连接。否则,会导致汇总数据的错误,并且执行时间也大大增加。需对结果中值为NULL的字段进行数学运算时,要对其进行替换处理。

 
图标索引 相关查询

 


 
CNKI小工具
在英文学术搜索中查有关from子句的内容
在知识搜索中查有关from子句的内容
在数字搜索中查有关from子句的内容
在概念知识元中查有关from子句的内容
在学术趋势中查有关from子句的内容
 
 

CNKI主页设CNKI翻译助手为主页 | 收藏CNKI翻译助手 | 广告服务 | 英文学术搜索
版权图标  2008 CNKI-中国知网
京ICP证040431号 互联网出版许可证 新出网证(京)字008号
北京市公安局海淀分局 备案号:110 1081725
版权图标 2008中国知网(cnki) 中国学术期刊(光盘版)电子杂志社