UnicodeDecodeError: ('utf-8' codec)读取csv文件[duplicate]
This question already has an answer here: 这个问题已经有了答案: UnicodeDecodeError when reading CSV file in Pandas with Python 3 answers 当用Python 3回答在...
【原创】 “duplicate connection name”
【Problem】 duplicate connection name 【Solution】 在Qt上使用SQLite的时候,如果第二次使用QSqlDatabase::addDatabase()方式时,就会出现以下错误提示: QSqlDatabasePrivate::addDatabase: dup...
[LeetCode] 217. Contains Duplicate 包含重复元素
Given an array of integers, find if the array contains any duplicates. Your function should return true if any value appears at least twice in the arr...
可靠地检测脚本是否在web worker中执行[duplicate]
This question already has an answer here: 这个问题已经有了答案: Any standard mechanism for detecting if a JavaScript is executing as a WebWorker? 4 answer...
为什么if (!condition) {console.log(condition)}显示true [duplicate]
This question already has an answer here: 这个问题已经有了答案: What is wrong with my date regex? [duplicate] 2 answers 我的约会regex怎么了?(重复)2的答案 I want...
c#高级控制台I/O [duplicate]
This question already has an answer here: 这个问题已经有了答案: Console.ReadLine(“Default Text Editable Text On Line”) 2 answers 控制台。ReadLine(“在线上的默认文...
r - 用地址[duplicate]替换缩写
This question already has an answer here: 这个问题在这里已有答案: Dictionary style replace multiple items 7 answers 字典样式替换多个项目7个答案 It might be a comm...
从数据库中选择数据后出现错误[duplicate]
This question already has an answer here: 这个问题已经有了答案: PHP parse/syntax errors; and how to solve them? 13 answers PHP解析/语法错误;如何解决它们呢?13个答案 ...
如何在JavaScript中创建哈希或字典对象[duplicate]
This question already has an answer here: 这个问题已经有了答案: JavaScript Hashmap Equivalent 17 answers JavaScript Hashmap相当于17个答案 I want to create...
使用方法名称inRuby [duplicate]的字符串/变量调用方法
Possible Duplicate:How to turn a string into a method call? 可能重复:如何将字符串转换为方法调用? Currently I have a code that is doing something like this 目前我有一个类...
MYSQL主键存在则更新,不存在则插入的解决方案(ON DUPLICATE KEY UPDATE)
经常我们使用的最简单的数据库操作就是数据的更新,删除和插入,对于批量删除和插入的方法相信大家都很清楚,那么批量更新估计有的人就不知道了,并且还有批量插入,在插入时若有主键冲突则更新的操作,这在EAV模式中应该会经常用到吧。曾在网上搜索相关资料,有介绍三种方法:第一种是插入时通过where条件查询该条...
如何在Windows控制台的python中打印unicode字符串[duplicate]
This question already has an answer here: 这个问题已经有了答案: Python, Unicode, and the Windows console 11 answers Python、Unicode和Windows控制台11回答 I'...
(转载)INSERT INTO .. ON DUPLICATE KEY 语法与实例教程
(转载)http://www.111cn.net/database/mysql/ON_DUPLICATE_KEY%20.htmINSERT语句末尾指定了ON DUPLICATE KEY UPDATE,并且插入行后会导致在一个UNIQUE索引或PRIMARY KEY中出现重复值,则执行旧行UPDATE...
Android Studio 错误 Duplicate files copied in APK META-INF/LICENSE.txt
1 .Duplicate files copied in APK META-INF/LICENSE.txt android { packagingOptions { exclude 'META-INF/LICENSE.txt' }}My logcat: log Execution ...
SQL中的ON DUPLICATE KEY UPDATE使用详解
一:主键索引,唯一索引和普通索引的关系主键索引主键索引是唯一索引的特殊类型。 数据库表通常有一列或列组合,其值用来唯一标识表中的每一行。该列称为表的主键。 在数据库关系图中为表定义一个主键将自动创建主键索引,主键索引是唯一索引的特殊类型。主键索引要求主键中的每个值是唯一的。当在查询中使用主键索引时,...
对象引用没有设置为Razor下拉列表中的对象实例[duplicate]
This question already has an answer here: 这个问题已经有了答案: What is a NullReferenceException, and how do I fix it? 33 answers 什么是NullReferenceExce...
如何检查被用户或ios杀死的ios应用[duplicate]
This question already has an answer here: 这个问题已经有了答案: How to know whether app is terminated by user or iOS (after 10min background) 2 answers ...
Duplicate entry '0' for key 'PRIMARY'
一般使用ORM时,提交新增实体时,mysql会出现此错误:Duplicate entry '0' for key 'PRIMARY'原因是插入语句,未提供主键的值,且主键是非自增长的。解决办法是,删除表中所有记录,设置主键为自增长。Duplicate entry '0' for key 'PRIMA...
data.table - 选择组中的前n行[duplicate]
This question already has an answer here: 这个问题在这里已有答案: How to extract the first n rows per group? 2 answers 如何提取每组前n行? 2个答案 As simple as i...
报错:SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry 'admin' for key 'username'
在提交注册信息的时候报错:SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry 'admin' for key 'username' 原因:主键冲突 从上图可以看出,用户名和邮箱必须唯一,如果填入重复的用户名或者...