Discover and read the best of Twitter Threads about #MySQL
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Welcome to my Saturday #linkdump, the third in an occasional series that may or may not be restricted to Saturdays, but which will ever be an ode to olde-timey #linkblogging of the sort practiced by our blogfathers, blogmothers, and other blogparents:
pluralistic.net/tag/linkdump/
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pluralistic.net/tag/linkdump/
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If you'd like an essay-formatted version of this thread to read or share, here's a link to it on pluralistic.net, my surveillance-free, ad-free, tracker-free blog:
pluralistic.net/2023/05/20/the…
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pluralistic.net/2023/05/20/the…
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Any fule kno that Saturday is #Caturday, and today's woke felinism comes from @GoingMedieval, earthiest of all the Medivelist Bloggers, author of the superb *Once and Future Sex*, all about dirty dirty medieval people and their filthy filthy habits:
pluralistic.net/2023/01/17/ren…
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pluralistic.net/2023/01/17/ren…
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The model will not perform well if training data is small, or noisy with errors outlier or if #data is not representative consist of irrelevant feature(garbage in garbage out) lastly neither too simple(result in #underfitting) nor too complex(results in #overfitting
#DataScience
#DataScience
Not enough training data.
Poor Quality of data.
Irrelevant features.
Nonrepresentative training data.
Overfitting and Underfitting.
#DataCleaningchallenge #MachineLearning #Deeplearning #DataAnalytics #DataVisualization #Python #Powerbi #SQL #MYSQL
analyticsvidhya.com/blog/2021/06/5…
Poor Quality of data.
Irrelevant features.
Nonrepresentative training data.
Overfitting and Underfitting.
#DataCleaningchallenge #MachineLearning #Deeplearning #DataAnalytics #DataVisualization #Python #Powerbi #SQL #MYSQL
analyticsvidhya.com/blog/2021/06/5…
10 articles to Guarantee success to you in 2023!
Open thread🔗(open tweet):
#Web3 #SmartContracts #serverless #Backend #cryptocurrency #fintech #Gamedev $ETH $BTC #Bitcoin #java #javascript #html #python #rustlang #firebase #ios #MySQL #startup #agile #php #AI #data #CSS #NodeJS
Open thread🔗(open tweet):
#Web3 #SmartContracts #serverless #Backend #cryptocurrency #fintech #Gamedev $ETH $BTC #Bitcoin #java #javascript #html #python #rustlang #firebase #ios #MySQL #startup #agile #php #AI #data #CSS #NodeJS
#programming with a fellow #dev can be more productive than you can envision!
medium.com/p/528d555f7846
medium.com/p/528d555f7846
Aprender a llevar nuestras aplicaciones a producción es algo que siempre nos cuesta. Hay Saas que nos ayudan, pero su precio puede ser elevado (sobre todo en proyectos pequeños o personales). Aquí una guía de cómo hacerlo por menos de 5€/mes.
Dentro hilo! 🧵
Dentro hilo! 🧵
0/14 - Nuestra infraestructura se compone de:
- Una API con @symfony
- Un cliente con #NextJS
- Una base de datos #MySQL
- Una API con @symfony
- Un cliente con #NextJS
- Una base de datos #MySQL
1/14 - Lo primero que debemos hacer es tener un esquema de lo que queremos. Esto nos ayudará a saber qué servicios usar
Q17 ) In problem where we need to find player with no of gold medals won by them only for players who won only gold medals.?
📓Code Snippets :
Q16 ) Write an SQL query to report all customers who never order anything.
Return the result table in any order.
Return the result table in any order.
Hey Folks 😃
📗Here are my Last 15 days Of SQL Questions Series Practice
🧵👇
📗Here are my Last 15 days Of SQL Questions Series Practice
🧵👇
Day 1 -
Day 2 -
Q15) A company's executives are interested in seeing who earns the most money in each of the company's departments. A high earner in a department is an employee who has a salary in the top three unique salaries for that department.
--- Write an SQL query to find the employees who are high earners in each of the departments.
Q12) Write a query that outputs the name of each credit card and the difference in issued amount between the month with the most cards issued, and the least cards issued. Order the results according to the biggest difference.
🫡Thankyou Shri @NickSinghTechSir For Creating Such a Great Platform
@DataLemurHQ For SQL & Data Science Learners
🖍️Code Snippet :
@DataLemurHQ For SQL & Data Science Learners
🖍️Code Snippet :
Q11) New TikTok users sign up with their emails & each user receives a text confirm to activate their Acc. Assume you r given below tables about email & text
Write query to display the id of the users who didn't confirm on the first day of sign-up but confirmed on the second day
Write query to display the id of the users who didn't confirm on the first day of sign-up but confirmed on the second day
🫡Thankyou Shri @NickSinghTechSir For Creating Such a Great Platform @DataLemurHQ For SQL & Data Science Learners
🖍️Code Snippet :
🖍️Code Snippet :
▶️You want to reach an intermediate SQL level inside a week 🔥
💯 I have the recipe for it
Yeah, no kidding. Seriously🫡
Source - Sidharth Kriplani Sir
🧵👇
💯 I have the recipe for it
Yeah, no kidding. Seriously🫡
Source - Sidharth Kriplani Sir
🧵👇
2⃣Day Two:
Average post hiatus (bit.ly/3WRPv2I)
Teams power users (bit.ly/3jCIggI)
Cards issued difference (bit.ly/3YUdhgi)
Average post hiatus (bit.ly/3WRPv2I)
Teams power users (bit.ly/3jCIggI)
Cards issued difference (bit.ly/3YUdhgi)
Day -🔟 on @facebook SQL Questions Series 🚀🎯
& Extremely sorry guys🙏 from last 2 days I am not posted but now onward i will Continue these series 😃🔥
🧵👇
& Extremely sorry guys🙏 from last 2 days I am not posted but now onward i will Continue these series 😃🔥
🧵👇
Q10) Assume you have an events table on app analytics. Write a query to get the app’s click-through rate (CTR %) in 2022. Output the results in percentages rounded to 2 decimal places.
🫡Thankyou Shri @NickSinghTechSir For Creating Such a Great Platform @DataLemurHQ For SQL & Data Science Learners
🖍️Code Snippet :
🖍️Code Snippet :
When you're just starting with #DataAnalytics, it's impossible to remember everything you need to know about #SQL.
Fortunately, there are amazing #cheatsheets so that you don't have to memorize the basic syntax and commands
Here are 7 SQL cheatsheets for handy reference:👇
Fortunately, there are amazing #cheatsheets so that you don't have to memorize the basic syntax and commands
Here are 7 SQL cheatsheets for handy reference:👇
1) SQL Cheatsheet by @swapnakpanda
This cheat sheet covers the basics like querying and joins, but also includes some data modeling and data definition commands as well.
Definitely worth checking out:
This cheat sheet covers the basics like querying and joins, but also includes some data modeling and data definition commands as well.
Definitely worth checking out:
Chapter 8: Grouping and Aggregate functions of #LearningSQL @OReillyMedia
This thread will be a brief summary and a short one.
Let's dive in
This thread will be a brief summary and a short one.
Let's dive in
1. GROUP BY is one of the most fundamental functions in #MySQL or any kind. It helps us to retrieve counts, distinct values and etc by certain categorical data.
An example:
An example:
2. If you need to filter your tables while using GROUP BY, generally you cannot use WHERE clause, instead use HAVING.
In this example we filtered the data after creating groups. If we'd have used WHERE before GROUP BY, server will raise an error.
In this example we filtered the data after creating groups. If we'd have used WHERE before GROUP BY, server will raise an error.
Let's continue with Temporal data, earlier we read strings and numeric data.
1. The major problem with dates is time zones, GMT , UTC. SQL server uses UTC.
2. There are various date data types in Sql;
DATE YY-MM-DD
DATETIME YY-MM-DD HH:MI:SS
TIMESTAMP same as datetime
Enter your dates as strings such as;
DATE YY-MM-DD
DATETIME YY-MM-DD HH:MI:SS
TIMESTAMP same as datetime
Enter your dates as strings such as;
Alright, let's get back to work. Feeling better already, and got some time to read Chapter III - Query Primer
Let's start
Let's start
First, let's select data for the queries. I'll go with my Coffee Quality repo, the data is from @KaggleDatasets, you can access it there.
Now, back to Chapter.
This chapter is basically about #MySQL statements. It covers select, from, where, group by, order by and having.
Now, back to Chapter.
This chapter is basically about #MySQL statements. It covers select, from, where, group by, order by and having.
2⃣ But first, it would be better to understand how SQL Server executes your queries. When we run a query, the server checks 3 things:
▶️ Permission to execute query
▶️ Permission to access database
▶️ Statement syntax
▶️ Permission to execute query
▶️ Permission to access database
▶️ Statement syntax
1⃣ Today, I'll continue with Chapter II. This chapter focuses on data types and creating / populating data.
Since I was aware of the data types, I try to summarize the chapter. For who are new to #SQL should read in detail.
For statistics related treads, see @levikul09.
Since I was aware of the data types, I try to summarize the chapter. For who are new to #SQL should read in detail.
For statistics related treads, see @levikul09.
2⃣ #MySQL Datatypes
1. Character data:
☑️ Fixed-length : right-pinned with spaces
☑️ Variable length : not padded, space consumption varies
i.e : char(20) - fixed ; varchar(20) variable length examples.
1. Character data:
☑️ Fixed-length : right-pinned with spaces
☑️ Variable length : not padded, space consumption varies
i.e : char(20) - fixed ; varchar(20) variable length examples.
3⃣ Character Sets are used for different languages with different letters
Returns a table with different char sets. If maxlen bigger than 1, the chars in that language are bigger than 1 bytes.
Returns a table with different char sets. If maxlen bigger than 1, the chars in that language are bigger than 1 bytes.
2/8 Isolate the resources from the internet (not publicly accessible)
3/8 Leverage security groups to control network traffic for the individual resources.
🧵 Today I decided to tackle a performance issue in our #MySQL Database.
We use timestamp columns for storing states (is paid, is invoiced, is shipped etc.) and clients would like to be able to filter by these states (see screenshot)
Thread below👇🏻
We use timestamp columns for storing states (is paid, is invoiced, is shipped etc.) and clients would like to be able to filter by these states (see screenshot)
Thread below👇🏻
Despite having indexes on all 4 of our timestamp columns, this query can become incredibly slow as data grows. Screenshot from first tweet is an example on 1 million records.
In order to optimize this, we can add a indexed boolean state column that concats all the timestamps.
In order to optimize this, we can add a indexed boolean state column that concats all the timestamps.
Notice the leading "1", this is simply to ensure no leading zeroes are stripped. Using a string column to combat this would result in worse performance, as querying integers is much faster.
This change means we can now query by the state column instead of the timestamp column.
This change means we can now query by the state column instead of the timestamp column.
10 Best practices in MySQL 🔥 🔥 🔥
Follow these best practices to make your queries faster and efficient
Note: Please research more about each topic before applying
Thread 🧵
#mysql #CodeNewbie
Follow these best practices to make your queries faster and efficient
Note: Please research more about each topic before applying
Thread 🧵
#mysql #CodeNewbie
🦋 1. Add Index key columns 🔥 🔥 🔥
🔸 Always index columns that you plan on searching on
🔸 Index the columns which are used in JOIN clauses so that the query returns the result fast
🔸 Do not use Index for many column, it will slow the Insert or Update
🔸 Always index columns that you plan on searching on
🔸 Index the columns which are used in JOIN clauses so that the query returns the result fast
🔸 Do not use Index for many column, it will slow the Insert or Update
🦋 2. LIMIT 1 When Getting a Unique Row 🔥 🔥 🔥
🔸Adding LIMIT 1 to your query can increase performance
🔸Reduces execution time because the database engine will stop scanning for records after it finds the first match
🔸Adding LIMIT 1 to your query can increase performance
🔸Reduces execution time because the database engine will stop scanning for records after it finds the first match
SQL dumps (database dumps) for #OSINT
Super short practical course.
Thread🧵🧵🧵
(12 tweets)
#sql #mysql #phpmyadmin
Super short practical course.
Thread🧵🧵🧵
(12 tweets)
#sql #mysql #phpmyadmin
(1/12)
In @GoogleHacking (exploit-db.com/google-hacking…) there are 176 dorks for searching SQL dumps, which may contain any confidential information.
Simple ex (pic 2):
ivanov ext:sql site:github.com
This query search all sql-files, which contain "ivanov" in #Github
In @GoogleHacking (exploit-db.com/google-hacking…) there are 176 dorks for searching SQL dumps, which may contain any confidential information.
Simple ex (pic 2):
ivanov ext:sql site:github.com
This query search all sql-files, which contain "ivanov" in #Github
(2/12)
Sometimes in this way it's possible find databases with information about orders, customers or employees. Inattentively, site owners forget to close them from indexing in robot.txt.
Such SQL-dumps may contain names, surnames, dates of birth, addresses, phone numbers.
Sometimes in this way it's possible find databases with information about orders, customers or employees. Inattentively, site owners forget to close them from indexing in robot.txt.
Such SQL-dumps may contain names, surnames, dates of birth, addresses, phone numbers.
NOT AGAIN ! A member of a #hacking forum has allegedly breached @dominos_india and got access to 13TB of internal files (from 2015-21), which he threatens to sell if a #ransom of 50 BTC is not paid 😨
#india #databreach #infosys #gdpr
#privacy
(1/5)
#india #databreach #infosys #gdpr
#privacy
(1/5)
Acc to him, he has internal files of 250 employees from IT, Legal, Finance, Marketing, Operations etc. Also customers details and 180M order details (name, ph number, email, delivery address, payment details) and 1M credit cards used to purchase on the @dominos app.
(2/5)
(2/5)
The post made by him mentions that, he will be selling the #breached data for 2 BTC or 8 BTC (according to the package one chooses). However if @dominos_india wants to prevent the data from getting sold, they will need to pay him a ransom of 50 BTC💰
(3/5)
(3/5)
Choosing the right tech stack is one of the most important decisions when building a software product.
The ability to scale quickly depends on many factors but having the proper tech stack may be the most important one.
(Thread) 👇
The ability to scale quickly depends on many factors but having the proper tech stack may be the most important one.
(Thread) 👇
1/ Tech stacks not only impacts the scalability in terms of performance but also provides flexibility and agility to evolve the product, eases the development of ecosystems, and attracts and retains talent.
2/ I am sharing in this thread, some of the components of our tech stack at @intraway that are working great for us.
With an explosion of software in the past few years, IMO, the tech stack of the future will see a LOT less custom code.
The attached poster/graphic summarizes my thoughts.
11 tweet thread follows... 🧵⬇️
The attached poster/graphic summarizes my thoughts.
11 tweet thread follows... 🧵⬇️
With 100+ launches on PH every day, there is a high probability you will find software that does what you need at a price point that works for you
These will be the first port of call for any process automation and new product functionality
Some examples coming up ...
These will be the first port of call for any process automation and new product functionality
Some examples coming up ...
Some tools provide functionality for your product
@getstream_io gives you newsfeed, @twilio gives you chat/SMS/calls, @keen_io enables reporting out of the box, @bannerbearHQ API creates bulk images. And so on
@getstream_io gives you newsfeed, @twilio gives you chat/SMS/calls, @keen_io enables reporting out of the box, @bannerbearHQ API creates bulk images. And so on
