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Search - "concat"
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Today, for fun, I wrote prime number generation upto 1000 using pure single MySQL query.
No already created tables, no procedures, no variables. Just pure SQL using derived tables.
So does this mean that pure SQL statements do not have the halting problem?
Putting an EXPLAIN over the query I could see how MySQL guessed that the total number of calculations would be 1000*1000 even before executing the query in itself and this is amazing ♥️
I have attached a screenshot of the query and if you are curious, I have also left below the plain text.
PS this was a SQL problem in Hackerrank.
MySQL query:
select group_concat(primeNumber SEPARATOR '&') from
(select numberTable.number as primeNumber from
(select cast((concat(tens, units, hundreds)+1) as UNSIGNED) as number from
(select 0 as units union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) unitsTable,
(select 0 as tens union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) tensTable,
(select 0 as hundreds union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) hundredsTable order by number) numberTable
inner join
(select cast((concat(tens, units, hundreds)+1) as UNSIGNED) as divisor from
(select 0 as units union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) unitsTable,
(select 0 as tens union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) tensTable,
(select 0 as hundreds union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) hundredsTable order by divisor) divisorTable
on (divisorTable.divisor<=numberTable.number and divisorTable.divisor!=1)
where numberTable.number%divisorTable.divisor=0
group by numberTable.number having count(*)<=1 order by numberTable.number) resultTable;9 -
What a fucking day!
So some many years ago, we placed a small and useful piece of code into a MySQL Query, which prefixes the order ids with a string and returns the value.
Basically
SELECT
CONCAT(“ORDER_PREFIX”, LPAD(order.id,5,’0’) AS order_reference
Now many years ago when this was a simple solution to a system that wasn’t expected to be running today, all went well, except today.... today that fucking line exceeded 5 digits
😓😍😓
I don’t know if I should be ashamed, or happy right now, a totally unfuture proof query that just rolled that little too far, or the fact that I’ve watch 100k orders role through this system.
Now for the clean up crew to do their job.... oh 🙁 that’s me too.
Now this doesn’t affect the order ids... so that’s something but external systems rely on that guy 😭5 -
When i was 15 i wanted to try myself at coding and hacking.
Yeah a bit ignorant i know.
Anyhow,i randomly found a python tutorial i believe.
Got things running and started the first tasks.
Create a var, associate a string. Create a second var and associate a new string.
Concat them and you get a new string with both of em together.
Then i told myself that this was fucking shit and i quit.
15 years later,i regret more and more that i let it go but what a fucking dumb tutorial that was...
17 years of coding and i would have been a fucking beast.15 -
I'm adding content to a schools moodle for an online CS course I am creating. The dev thought it would be a good idea to have 250+ page requests so I get to wait for 10seconds everytime I click the next button.
Still no response to my email asking him to uglify and concat.
At least I'm getting paid by the hour. -
Teaching new devs, hired straight from India.
This is today.
Bug1: We have four lists, each item in these lists has a variable called "Charge". This var is a double and we need to convert it to currency.
Dev creates fifth list called "All lists" and converted it's charge to currency then questioned why it didn't work.
I explained, his solution? Convert each list into currency.
I explained that's wrong and told him what he needed to do. He did List1:Charge into currency, but left his other conversion in place just in case.
I walked him through fixing it which took 10 times as long as necessary, only to find out he randomly converted four booleans into currency for no reason.
Bug2: we take integer, convert to string and concat "Months" on the end.
Doesn't work for him, tells me he doesn't know why.
I told him that he's not outputting the variable that we did it to, he is instead outputting a custom variable he made and didn't do anything to.
Bug 3: followup to #2, he fixed it as I instructed, but then added months as static text to the output so now it reads "Months months".
Bug 4: to make his code cleaner, he presses enter in the text box. Unfortunately he did that IN A STRING so his output is full of random /r/n
How do you guys deal with coworkers like this? He isn't new, this is supposed to be an experienced developer. Im only in my 2nd year23 -
JS method names I still can't remember, even after 6 years of writing in it:
append is called concat,
any is called some,
all is called every,
contains is called includes
I always have to pause for a good long while or look it up when I need to use any of these is annoying, but my brain refuses to adapt to these names.4 -
Swift SUCKS
Why?
Because of its absolutely useless complexity...
a total simple thing: i have a string and want to concat a integer with it, so:
var x = stringVar + intVar; right? NO
its var x = stringVar + String(intVar);
or getting the index of a element in a array?
var index = array.indexOf(element); thats logic, right??? Not for swift, gotta go with: var index = array.index(of: element); WTF??!!
And all the other shit: nil instead of null, int++? Nope.
And there are SO MANY MORE things, where u just think, Apple really though different........than all normal coding languages.......
I´ll honestly rather learn C and recode Ios or have a look at objective-c...14 -
!@#GDSGA!Q@#@
In my absolute lack of genius, I just lost way too much time finally realizing that in C# linq-to-objects removes duplicates when you use Union().
At one point I knew this, but I forgot about it because I never want duplicates, slowly forgetting what Union() was doing.
*This time* however, the duplicates are required and it all goes to crap without them.
Save me, Concat()!
You can run but you can't hide from noobery.
Blahb;asdfabnahsdfa.3 -
I discovered a language I didn't know AND i like.
It's not under active development anymore, but I decide it has a nice syntax. It's made by the writer of craftinginterpreters. There are still people writing some extensions for it.
I decided to implement socket support in it.
That went very well and the result is just BEAUTIFUL. But now, i have a collection of socket functions that require a file descriptor (sock) for every function like write, read and close. We're not living in the 90's. I want to do sock.send(), sock.write() and sock.close(). So socket as an object.
I wrote a wrapper and it is freaking TWO times slower! Hows that even possible.
I've made wrapping to object optional now. Bit disappointing.
The language shows off with benchmarks on their page. Their fibers can even be faster than Elixr. Yeah, if you only use the fiber and nothing else from language. I benchmarked string concat for example against python: 1000 times slower or so.
The source code of wren is so freaking beautiful. Before Lua was my favorite language regarding source. The extensibility is so great that I prefer to work on this one instead of my own language. They kinda made exactly what I wanted. I can't beat that.
For if you're interested: https://wren.io/
The slot way of communicating between host language (C) and child language (wren) seems odd at beginning but i became fan of it.
Thanks for listening to my ted talk.
What's your opinion about wren (syntax)?25 -
You win this round SQL.... but I'll be back... and when I do I'll get this stupid join and concat to work the way I want. YOU'LL SEE SQL!!!!
...If I ever buy an SQL book like I keep talking about...
-deploy not entirely janky but also not ideal solution- -
When gulp build (expressjs + browsersync + browserify + uglify + gzip + gulp-zip + gulp-tar) perfectly compiles your code, minify and concat all js, gzipped them, minify images, package the files into a .zip and .tar... and refresh your browser 😍
you begin to have faith that its gona be a nice day ahead -
If only more devs would use short, yet concise, modern constructs instead of archaic ones.
For example in C#: using lambdas, extension methods, LinQ,.. much easier to read through if you know how these work, rather than having to spend all day scanning tedious for-loops and over-engineered classes your colleagues wrote who don't know any better.
Examples:
vs.foreach(v => console.write(v));
initialList = secondList.Where(p => initialList.Contains(p, valueComparer))
.Concat(initialList.Where(p => !secondList.Contains(p, valueComparer))).ToList(); -
Just had the displeasure of working with knockout, how is it that a JS library can be soo fundamentally flawed that you cannot concatenate a string with a variable inside a binding definition.
All I want to do is create a css class using the value of a variable inside an itteration with a prefix, so that I can write other less bad code to get around KO's other limitation, but no, you cannot concat, why would I want to do that inside of javascript.
Useless pile of tosslet2 -
Ok so.. thoughts on MySQL,
SELECT max(column_name) from table_name;
Outputs the max value in the column by kinda traversing the whole column huh... Recursive🤔
While
SELECT concat(column_name) from table_name; outputs simple endl separated srrings. . .. no recursion. PHP backend sucks
😣7