SEARCH KEYWORD -- insert


  Select top 3 values from each group in a table with SQL

Yesterday, my friend Liu Bing asked me a question about how to select top 3 values for each person in a database table using SQL. I think this question is interesting and it deserves some thoughts. Here I record down how to solve this issue. Assume we have a table which has two columns, one column contains the names of some people and the other column contains some values related to each person. One person can have more than one value. Each value has a numeric type. The question is we want to se...

   SQL,Correlated query,top 3     2013-05-23 03:21:25

  How to optimize MySQL insert statement

For a big data system, one problem is the data access efficiency, one more problem is that the data insertion is very slow. We had a service system, the data loading process would take 4-5 hours. This time consuming operation is risky since if the program is interrupted during the loading process, it might be rerun, this will be troublesome. So it's necessary to improve the insertion efficiency for big data systems. Here we provide two optimization suggestions. 1. Combine multiple insert stateme...

   MySQL,insert,optimization     2012-10-24 22:03:13

  A simple tutorial on GoLang connecting to Clickhouse

Go, also known as Golang, is a statically-typed, concurrent programming language created by Google. ClickHouse is a high-performance, column-oriented database management system that can be used for real-time data analysis. This tutorial will provide a deep dive into how to connect to ClickHouse from a Go program, including how to perform common database operations such as SELECT and INSERT statements. Before proceeding, it is assumed that you already have Go and ClickHouse installed on your mach...

   GOLANG,CLICKHOUSE,TUTORIAL     2023-02-11 07:05:36

  A trap in PDOStatement::bindParam

First, let's check out below codes: <?php $dbh = new PDO('mysql:host=localhost;dbname=test', "test"); $query = <<prepare($query); $bind_params = array(':username' => "laruence", ':password' => "weibo"); foreach( $bind_params as $key => $value ){ $statement->bindParam($key, $value); } $statement->execute(); What is the SQL executed finally? Is there any problem with above codes? Many people may think the query executed is : INSERT INTO `user` (`username`, `password...

   PHP,Trap,bindParam     2013-08-29 10:48:55

  Add page number anywhere in word document

Have you ever frustrated when you want to add page number in a Microsoft word document start from page 2 or later. The way to ease you is to add sections to the word document in which page you want to add page number. The procedures are (in Word 2007) :1. Goto Page Layout->Breaks->Section breaks.2. In Section Breaks zone, you can choose Next Page and some others way to set sections.3. Then when you want to add the page number into next section. Go to Insert->Page Number->Format ...

   Office 2007, Word, Page number, Section,     2011-04-08 04:00:53

  To our youth

Youth is the best period in our life for most of us. We have dreams, passions and energies. We can work day and night for our dreams.We can hang out with friends the whole day. But there will always be a day when we are not young anymore, our youth will pass by. We will not be able to go back to our youth any more. Do you have anything to say about your youth? Recently, a Chinese IT engineer @本座 wrote a short code snippet to describe our youth. Here we share what she writes: public vo...

   Youth,Programming,Rollback     2013-05-02 05:26:56

  Never ever touch a programmer

This is a technical license plate block example. We don't know whether it is working or not, however, the idea is very good. When you drive through some of the junctions, the camera captures the license number and convert it into text with OCR, and then insert them into the database. Therefore, this license plate on the car becomes a SQL injection. This picture tells us -- never trust user input.Author : 陈皓 Source : http://coolshell.cn/articles/6639.html#more-6639...

   Programmer,SQL injection     2012-04-21 01:19:48

  TikTok confirms to sue US government

TikTok confirmed on Saturday to sue US government and US president Donald Trump over Trump administration's executive order on potentially banning TikTok in US. This Chinese short video app is the most downloaded app on App Store and PlayStore over past few months and has gained extremely high popularity among American youths. The parent company ByteDance claimed that the government's ban is illegal and hurts the interests of America people. "Even though we strongly disagree with the administra...

   BYTEDANCE,TIKTOK,US GOVERNMENT     2020-08-22 22:27:29

  Web Security: In-Depth Explanation of X-XSS-Protection

What is X-XSS-Protection X-XSS-Protection is an HTTP response header designed to enable or configure built-in cross-site scripting (XSS) filters in certain versions of Internet Explorer, Chrome, and Safari. The purpose of these filters is to detect reflected XSS attacks in the response and prevent the loading of pages, thereby protecting users from such attacks. The X-XSS-Protection response header was initially introduced by Microsoft in Internet Explorer 8 to control the browser's XSS filter. ...

   X-XSS-PROTECTION,WEB SECURITY,CONTENT SECURITY POLICY,XSS,CSP     2023-11-29 01:48:40

  SkipList in Go

Algorithmic thinking is the must-have in the coding world, so I have been keeping the routine of algorithm practice every week, consolidating my knowledge of data structures on one hand, and improving my coding skills as well. A difficult one happened to be stuck in my mind- Implement SkipList with Go, which took me quite a weekend. Below is the front-line report of how I finally got the hang of it. First, from its concept. Wiki has explained it well. a skip list is a probab...

   GOLANG,SKIPLIST     2022-04-05 02:21:59

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