alias | 易学教程

Oracle rename columns from select automatically?

阅读更多关于 Oracle rename columns from select automatically?

问题 I have 2 tables with the following fields. Table1 AA BB CC DD Table2 AA CC EE Query Select t1.*, t2.* from table1 t1, join table2 t2 on table1.DD = table2.EE My data columns back with the following column names: AA, BB, CC, DD, **AA_1**, **CC_1**, EE I don't want the column names like that. I want them to have the table name prefixed in the names of common (or all columns). I could fix this with: select t1.AA as t1_AA, t1.BB as t1_BB, t1.CC as t1_CC, t1.DD as t1_DD, t2.AA as t2_AA, t2.CC as

五周第三次课（4月20日） 8.1 shell介绍 8.2 命令历史 8.3 命令补全和别名 8.4 通配符 8.5 输入输出重定向

阅读更多关于五周第三次课（4月20日） 8.1 shell介绍 8.2 命令历史 8.3 命令补全和别名 8.4 通配符 8.5 输入输出重定向

【推荐】2019 Java 开发者跳槽指南.pdf(吐血整理) >>> 第八章 shell基础 8.1 shell介绍 Shell是一个命令解释器，提供用户和机器之间的交互，支持特定的语法，比如逻辑判断、循环。每个用户都可以有自己特定的shell，CentOS7的默认shell为bash（Bourne Agin Shell），常见的还有zsh（power-shell）、ksh（Korn shell）。 8.2 命令历史（history） history命令语法： history [-c] -c：=clear 清除内存中的命令，不能删除配置文件中的历史命令 [root@adai003 ~]# history 1 ls 2 ls /tmp/ 3 ls /boot/ 4 ls / 5 dhclient …… [root@adai003 ~]# ls /root/.bash_history /root/.bash_history history的家目录显示使用过的命令历史，默认保存1000条使用过的命令（注：此令需要是在正常关机操作情况下的处1000条命）！ history环境变量变量HISTSIZE [root@cham2 ~]# echo $HISTSIZE 1000 该变量决定命令历史保存的命令的数目。定义变量HISTSIZE [root@cham2 ~]# [[root

Facebook social plugin comments after URL change

阅读更多关于 Facebook social plugin comments after URL change

问题 Just a simple question, I had facebook comments integrated in my page here: http://www.bbcnepalidrama.com/main/node/3 Now I have changed the URL alias like this: http://www.bbcnepalidrama.com/main/about I have also set a 301 redirect in the old URL which redirects to the new one. The Question is how do I get the old comments in this URL? They are missing now. 回答1: I think, that these comments will be forever associated with that URL and since you've changed it, as far as FB is concerned you

Are there standard aliases for modules in Python?

阅读更多关于 Are there standard aliases for modules in Python?

问题 Following the guidelines proposed in this post, I am changing all the from module import function function(agt) by: import module as mdl mdl.function(agt) in my codes. I am trying to use commonly used aliases rather than personal ones. Is there a list of some kind on the internet summing-up all well-used aliases ? For instance, these appear to be pretty common: import numpy as np import math as m import matplotlib.pyplot as plt What about aliases for scipy.linalg , time , scipy.io , cmath and

How to avoid quotes around table aliases in jOOQ

阅读更多关于 How to avoid quotes around table aliases in jOOQ

问题 I have the following select-query creation: final DSLContext create = DSL.using(..., SQLDialect.POSTGRES); create .select(DSL.field("identifier"), DSL.field("name"), create.selectCount() .from(DSL.table("person")) .where(DSL.field("identifier").eq(DSL.field("personOuter.identifier"))) .asField("count")) .from(DSL.table("person").as("personOuter")) jOOQ generates the following query: select identifier, name, (select count(*) from person where identifier = personOuter.identifier) as "count"

Bash function calling command given as argument

阅读更多关于 Bash function calling command given as argument

问题 How do you write a function in bash that executes the command that it is given as an argument, where The given command may be an alias Arguments must be passed on exactly as given; no evaluating may be done In other words, how to write an as-transparent-as-possible wrapper function. The goal of the wrapper function could for example be to set the current directory before and after the given command, and/or set environment variables, or time how long the given command takes,... As a simple

Alias or Reference in ResourceDictionary

阅读更多关于 Alias or Reference in ResourceDictionary

问题 I'm looking for a way to essentially give an item in a ResourceDictionary multiple keys. Is there a way to do this? <DataTemplate x:Key="myTemplate" ... /> <AliasedResource x:Key="myTemplateViaAlias" Target="myTemplate" OR_Target={StaticResource myTemplate} /> When I call TryFindResource("myTemplateViaAlias") I want to get myTemplate out. I suppose I could create an AliasedResource class myself and dereference it in code when I get it out of the dictionary, but I'd rather not do that if there

what is CakePHP model alias used for?

阅读更多关于 what is CakePHP model alias used for?

问题 In user model: var $hasMany = array( 'Photo' => array( 'className' => 'Photo', 'foreignKey' => 'owner_id', ... ), ); In photo model: var $belongsTo = array( 'Owner' => array( 'className' => 'User', 'foreignKey' => 'owner_id', ... ), ); Here one user has many photos. So what my question is that here the alias name is 'Owner', which make me clear to understand the exact meaning of 'User', but is this the only reason to use alias? does it affect 'Photo' in user model? or how to use 'Owner' in/by

To calculate sum() two alias named columns - in sql

阅读更多关于 To calculate sum() two alias named columns - in sql

问题 To calculate sum() of two temp column names declared in query - in SQL stud table has only two columns m1,m2 . total and total1 is given as temp name. select m1, m2, SUM(m1) + SUM(m2) as Total, SUM(m1) + SUM(m2) as Total1 from stud group by m1, m2 How to calculate grandtotal as sum(total)+sum(total1) with the column name declared as temp name for the query to execute. With cte dosn't support duplicate column names? How to make use of it to support duplicate columnname 回答1: You can't do it

Why use class aliases?

阅读更多关于 Why use class aliases?

问题 Why would we use the class_alias function? For example: Class Test { public function __construct(){ echo "Class initialized"; } } class_alias("Test", "AnotherName"); $instance = new AnotherName(); # equivalent to $instance = new Test(); According to the manual, "The aliased class is exactly the same as the original class." What is this useful for? 回答1: Surprisingly, nobody has mentioned the obvious reason why one would do this: the use keyword can only be used in the outmost scope, and is