文章整合

mysql使用in函数的一个小问题

使用mysql时候发现的一个小问题，要注意变量类型，该是字符串的加上引号登录后复制 '登录后一键下载全文代码' select '3xfdff' in 3 / 返回 1 select '3xfdff' in '3' / 返回 0 1. 2. 还是不知道具体原因是啥，总之下次自己多注意吧
2022-08-05 06:27【51CTO】
阅读更多
《基于R语言的自动数据收集》--第3章 XML和JSON

Mark~ 明天填坑
2022-08-05 06:27【51CTO】
阅读更多
游戏思考19：游戏多维计算相关：点乘、叉乘、点线面距离计算

文章目录一、点乘 2 1）公式 1 3 2）要求 2 11 3）几何意义 3 15 二、叉乘 40 1）叉乘公式 1 41 2）几何意义（1、构建法向量，2、计算平行四边形面积） 212 60 3）以leetcode题举例（这里没有z轴，故z轴坐标计算的值都为0） 3leetcodezz0 84...
2022-08-05 06:26【谢白羽】
阅读更多
MySQL：连接查询 | 内连接，外连接

文章目录连接查询 2 场景一：内连接查询 12 表的创建 21 查询示例 44 效率问题 90 外连接查询 122 左连接查询 125 右连接查询 142 示例 160 待补充。。 179 连接查询连接查询分为内连接查询和外连接查询 https://img blog.csdnimg.cn/d2...
2022-08-05 06:27【_索伦】
阅读更多
MySQL：order by排序查询，group by分组查询

文章目录 order by查询 order by 2 group by分组查询 group by 41 性能问题 85 order by查询即按照字段进行升序或降序查询，默认是升序，可以根据 asc 和 desc后缀来指定。示例：源数据 https://img blog.csdnimg.cn...
2022-08-05 06:27【_索伦】
阅读更多
2022 Fusion Welding and Thermal Cutting Operation Certificate Exam Questions and Mock Exams

Source of question bank: Safety Production Mock Test Yitong Public Number Mini Program 2022 Melting Welding and Thermal Cutting Test Questions is the ...
2022-08-05 07:03【yangfany01】
阅读更多
AI + video technology helps to ensure campus security, how to build a campus intelligent security platform?

I. Industry Background Recently, a wounding incident occurred in a kindergarten in Jiangxi Province. This accidental story made campus safety become t...
2022-08-05 07:03【TSINGSEE】
阅读更多
IO process thread -> communication between processes -> day7

Catalog 1. AB communication function%E4%B8%80%E3%80%81%20AB%E9%80%9A%E4%BF%A1%E5%87%BD%E6%95%B0 1.1 A process function 1.1%20A%E8%BF%9B%E7%A8%8B%E5%87...
2022-08-05 07:03【Whale calls me to take care of the sea QAQ】
阅读更多
Mysql master-slave delay reasons and solutions

MySQL master-slave replication first explain that there are mainly two ways of binlog recording (excluding Mixed) statement SBR Operation-based SQL st...
2022-08-05 07:03【Eat well without getting fat】
阅读更多
Shiny04---Application of DT and progress bar in shiny

After looking for a long time, I finally found a way to display the progress bar in shiny, go directly to the demo, and record it.UI script after logi...
2022-08-05 07:03【51CTO】
阅读更多
2022 crane driver (limited bridge crane) exam question bank and simulation test

Source of question bank: Safety Production Mock Exam Easy Access Official Account Mini Program 2022 Crane Driver Restricted Overhead Crane Review Ques...
2022-08-05 07:04【yangfany01】
阅读更多
Falsely bamboo brother today and found a localization of API to use tools

*️Author's homepage: Xiaoxuzhu *️Author's introduction: Hello everyone, I'm Xiaoxuzhu.High-quality creators in the Java field*, CSDN blog experts*, Hu...
2022-08-05 07:04【Xiaoxuzhu】
阅读更多
TCP sticky packet unpacking problem + solution

https://img blogs. Csdnimg. Cn/c36de7843feb46edb4bb9d94ad1b6b99 jpeg why the TCP and UDP is not stick pack * 1 ️ ⃣ because UDP packets have protect bo...
2022-08-05 07:04【Talking about knowledge】
阅读更多
After working for 3 years, I recalled the comparison between the past and the present when I first started, and joked about my testing career

Foreword I have been engaged in testing for more than 3 years. Today I want to talk about the comparison between when I first started and now. Althoug...
2022-08-05 07:04【two black】
阅读更多
[Tool Configuration] Summary of Common Uses of VSCode

To save automatic indentation like VS 1. ctrl + shift + P 2. Enter user setting 3. Enter format 4. Click to edit in settings.json 5. Add, split at the...
2022-08-05 07:04【OctalZero】
阅读更多
Put Cloudflare on the website (take Tencent Cloud as an example)

What does Cloudflare do? Cloudflare can mainly do the following things: CDN DDNS Speaking of human words, what are the functions of the above: Improve...
2022-08-05 07:04【Talking about knowledge】
阅读更多
binary search tree problem

1 Original problem description Binary search tree HDU 3791 Virtual Judge 3791 3791 'Binary search tree HDU 3791 Virtual Judge' 2 Input and output 1 In...
2022-08-05 07:04【Chengqiuming】
阅读更多
RNote108---Display the running progress of the R program

Originally, I wanted to find a way to display the running progress of the program in shiny, but I only saw ~Whatever that shows the progress of the lo...
2022-08-05 07:04【51CTO】
阅读更多
Bluetooth gap protocol

// Data message/ / (It is defined by the gap layer starting from advdata in the payload, and it was defined by the ll layer before) Please add a pictu...
2022-08-05 07:05【aningxiaoxixi】
阅读更多
专用机终端安装软件后报IP冲突

飞腾的终端机安装deb的客户端包，安装完成后能使用，但是终端机重启后网络报ip地址冲突。
2022-08-05 06:39【墨天轮】
阅读更多