w将查询结果赋值给本地变量. http://dev.mysql.com/doc/refman/5.7/en/stored-program-variables.html Results from queries can be retrieved into local variables using SELECT ... INTO var_list or by opening a cursor and using FETCH ... INTO var_list. See Section 14.2.9…

Principle The most powerful technique for minimizing the scope of a local variable is to declare it where it is first used. Nearly every local variable declaration should contain an initializer. Note If a variable is initialized by a method that thro…

Implicitly Typed Local Variables It happens time and time again: I’ll be at a game jam, mentoring students, or just showing a friend some Unity C# code, and I’ll type something like this: var controller = GetComponent<CharacterController>(); They’ll…

内部类参考 A local class has access to local variables. However, a local class can only access local variables that are declared final. When a local class accesses a local variable or parameter of the enclosing block, it captures that variable or paramete…

每个栈帧中包含: 局部变量表(Local Variables) 操作数栈(Opreand Stack) 或表达式栈 动态链接 (Dynamic Linking) (或指向运行时常量的方法引用) 动态返回地址(Return Address) (或方法正常退出或者异常退出的引用的定义) 一些附加信息 局部变量表 局部变量表也被称之为局部变量数据组或本地变量表 定义为一个数字数组,主要用户存储方法参数和定义在方法体内的局部变量,这些数据类型包括各类基本数据类型.对象引用(reference),以及re…

关于 local variable 'has' referenced before assignment 问题 今天在django开发时,访问页面总是出现错误提示“local variable 'has' referenced before assignment”,查了一下资料,好像是说无法访问这个变量,检查一下代码我的视图是这样写的: def MusicTable(request):    MUSICIANS = [          {'name': 'Django Reinhardt',…

目录 . 漏洞描述 . 漏洞触发条件 . 漏洞影响范围 . 漏洞代码分析 . 防御方法 . 攻防思考 1. 漏洞描述 齐博在/inc/common.inc.php使用$$_key=$value.extract等逻辑实现了外部输入变量的本地注册,这是模拟了GPC的功能,但同时也引入"本地变量覆盖"."本地变量未初始化"的安全风险 齐博CMS中的漏洞文件/inc/common.inc.php使用 @extract($_FILES, EXTR_SKIP)来注册$_FILE…

<insert id="create" parameterType="models.entities.CategoryEntity"> set @catId := (select categoryId from Categories limit 1); insert into Categories(CategoryId, Title, LeftValue, RightValue) values(@catId, 'Test in', 1,2); ....…

the problem definitly apears after changing toolchain from gcc 4.6 to gcc 4.8. here's a solution with all details, no extra explanation needed: http://stackoverflow.com/questions/12595631/debugging-with-gdb-on-a-program-with-no-optimization-but-still…

可能是上次编译后  code未再修改过. 试试 随便 输入一个空格,然后F9…

前几天使用lamdba时,报了一个这个错,原因是在lamdba体中使用了一个变量,觉得很奇怪! 今天在读这本书的时候,又看到了这个解释,这里有了更深刻的理解,总结一下: 在jdk1.8之前在使用匿名内部类的时候方法里面的变量必须需要加final 否则是会报错的,但是jdk1.8放松了这个限制,可以使用非final修饰,但是这个变量,是不允许另外赋值的,否则lamdba体重也会报错,如图: 换句话说,Lambda 表达式引用的是值,而不是变量.所以在lamdba和匿名内部类中使用变量不能被改变 如…

LAST UPDATE:     1 Dec 15, 2016 APPLIES TO:     1 2 3 4 Oracle Database - Enterprise Edition - Version 7.0.16.0 and later Oracle Database - Standard Edition - Version 7.0.16.0 and later Oracle Database - Personal Edition - Version 7.1.4.0 and later I…

转:https://googleprojectzero.blogspot.com/2017/12/apacolypse-now-exploiting-windows-10-in_18.html aPAColypse now: Exploiting Windows 10 in a Local Network with WPAD/PAC and JScript by Ivan Fratric, Thomas Dullien, James Forshaw and Steven Vittitoe Int…

问题描述,在Action.c里定义数组时如果数组长度过长,如char a[1024*1024]运行时即会报错: 问题原因及解决方法如下: 1. VuGen对于局部变量可以分配的最大内存为64K,如果想分配空间大于64K的变量的话,需要通过如下方法: VuGen has a limitation of 64K for local variables. If you want to declare a variable larger than 64K: a. 将其定义为全局变量,Declare it…

背景 使用 Android Studio 开发 Android 有一段时间了,偶尔会碰到 AS 在一些私有变量上有黄色高亮提示Field can be converted to a local varible,有些强迫症的我还是不希望看到这个黄色的高亮.百度没查到什么有用的信息,还是用谷歌搜到了一些解答. 解析 Field can be converted to a local varible 的完整说明是(纯手打): This inspection searches for redundant…

转载自:https://veerasundar.com/blog/2010/11/java-thread-local-how-to-use-and-code-sample/ Thread Local is an interesting and useful concept, yet most of the Java developers are not aware of how to use that. In this post, I’ll explain what is Thread Loca…

Performance Considerations for Entity Framework 5 By David Obando, Eric Dettinger and others Published: April 2012 1. Introduction Object-Relational Mapping frameworks are a convenient way to provide an abstraction for data access in an object-orient…

数据类型 日期时间类型 DATE(日期) DATE 数据类型由年.月.日信息组成,表示一个日期值. DATA 类型的默认格式为‘YYYY-MM-DD’. YYYY 表示年, MM 表示月而 DD 表示日.时间值的范围从 0001-01-01 至 9999-12-31. 数据类型扩展 除了内置的SQL数据类型,在SQLScript里用户可以自定义一些表类型的数据类型 标准数据类型 SQLScript类型系统是基于SQL-92类型系统的,它支持以下基础数据类型: Numeric types: TIN…

引用自:http://rusanu.com/2013/08/01/understanding-how-sql-server-executes-a-query/ Understanding how SQL Server executes a query August 1st, 2013 If you are a developer writing applications that use SQL Server and you are wondering what exactly happens…

Lua 5.1 参考手册 by Roberto Ierusalimschy, Luiz Henrique de Figueiredo, Waldemar Celes 云风 译 www.codingnow.com Copyright © 2006 Lua.org, PUC-Rio. All rights reserved. 1 - 介绍 Lua 是一个扩展式程序设计语言,它被设计成支持通用的过程式编程,并有相关数据描述的设施. Lua 也能对面向对象编程,函数式编程,数据驱动式编程提供很好的支持.…

http://www.onjava.com/pub/a/onjava/2001/05/30/optimization.htmlComparing the performance of LinkedLists and ArrayLists (and Vectors) (Page last updated May 2001, Added 2001-06-18, Author Jack Shirazi, Publisher OnJava). Tips: ArrayList is faster than…

一. Bulk 概述 本来只想测试一下Bulk Collect 和update性能的,但发现Bulk 的东西还是很多的,在OTN上搜了一些,整理如下. 1.1 Bulk Binding 和 Bulk SQL From:  http://download.oracle.com/docs/cd/E11882_01/appdev.112/e17125/adfns_packages.htm#ADFNS343 Oracle Database uses two engines to run PL/SQL b…

1. Introduction 1.1. About 1.2. Sphinx features 1.3. Where to get Sphinx 1.4. License 1.5. Credits 1.6. History 2. Installation 2.1. Supported systems 2.2. Compiling Sphinx from source 2.2.1. Required tools 2.2.2. Compiling on Linux 2.2.3. Known comp…

http://wiki.nginx.org/HttpLuaModule#Directives Name ngx_lua - Embed the power of Lua into Nginx This module is not distributed with the Nginx source. See the installation instructions. Status This module is under active development and is production…

https://www.codeproject.com/Articles/630346/Understanding-how-SQL-Server-executes-a-query https://www.codeproject.com/Articles/732812/How-to-analyse-SQL-Server-performance     This article will help you write better database code and will help you ge…

In particular embodiments, a method includes, from an indexer in a sensor network, accessing a set of sensor data that includes sensor data aggregated together from sensors in the sensor network, one or more time stamps for the sensor data, and metad…

1. CentOS系统安装openresty 你可以在你的 CentOS 系统中添加 openresty 仓库,这样就可以便于未来安装或更新我们的软件包(通过 yum update 命令).运行下面的命令就可以添加我们的仓库: $ sudo yum install yum-utils $ sudo yum-config-manager --add-repo https://openresty.org/package/centos/openresty.repo 然后就可以像下面这样安装软件包,比如…

转载来自: http://www.infocool.net/kb/PHP/201607/168683.html a 函数 说明 abs 绝对值 acos 反余弦 acosh 反双曲余弦 addcslashes 以 C 语言风格使用反斜线转义字符串中的字符 addslashes 使用反斜线引用字符串 apache_child_terminate 在本次请求结束后终止 apache 子进程 apache_getenv 获取 Apache subprocess_env 变量 apache_get_mo…

QUESTION 13 View the Exhibit.Examine the following command that is executed for the TRANSPORT table in the SH schema:SQL> SELECT DBMS_STATS.CREATE_EXTENDED_STATS('sh', 'customers_obe', '(country_id,cust_state_province)') FROM dual;Which statement des…

Android Lint Checks Here are the current list of checks that lint performs as of Android Studio 2.3 dev:     Correctness ===========   AdapterViewChildren ------------------- Summary: AdapterViews cannot have children in XML   Priority: 10 / 10 Sever…