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How to use GROUP_CONCAT in a CONCAT in MySQL
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select id, group_concat(`Name` separator ',') as `ColumnName`
from
(
select
id,
concat(`Name`, ':', group_concat(`Value` separator ',')) as `Name`
from mytbl
group by
id,
`Name`
) tbl
group by id;
You can see it im...
Using Gulp to Concatenate and Uglify files
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It turns out that I needed to use gulp-rename and also output the concatenated file first before 'uglification'. Here's the code:
var gulp = require('gulp'),
gp_concat = require('gulp-concat'),
gp_rename = require('gulp-rename'),
gp_uglify = require('gulp-uglify');
gulp.task(...
String concatenation: concat() vs “+” operator
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Firstly, there's a slight difference in semantics. If a is null, then a.concat(b) throws a NullPointerException but a+=b will treat the original value of a as if it were null. Furthermore, the concat() method only accepts String values while the + operator will silently convert the argument to a ...
Redis strings vs Redis hashes to represent JSON: efficiency?
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> redis.pipelined{ 10000.times{ |i| redis.me_set( "t:#{i}", txt[rand(50000), 63] ) } }; :done
=> :done
> ap redis.info(:memory)
{
"used_memory" => "1251944",
**"used_memory_human" => "1.19M"**, # ~ 72b per key/value
.....
}
> redis.fl...
MySQL and GROUP_CONCAT() maximum length
I'm using GROUP_CONCAT() in a MySQL query to convert multiple rows into a single string.
However, the maximum length of the result of this function is 1024 characters.
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MySQL Results as comma separated list
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You can use GROUP_CONCAT to perform that, e.g. something like
SELECT p.id, p.name, GROUP_CONCAT(s.name) AS site_list
FROM sites s
INNER JOIN publications p ON(s.id = p.site_id)
GROUP BY p.id, p.name;
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Node.js vs .Net performance
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Completed 100000 requests.
Total requests sent: 100000
Concurrent threads: 1000
Total completed requests:...
How to concatenate two MP4 files using FFmpeg?
I'm trying to concatenate two mp4 files using ffmpeg. I need this to be an automatic process hence why I chose ffmpeg. I'm converting the two files into .ts files and then concatenating them and then trying to encode that concated .ts file. The files are h264 and aac encoded and I'm hoping to kee...
GROUP_CONCAT ORDER BY
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You can use ORDER BY inside the GROUP_CONCAT function in this way:
SELECT li.client_id, group_concat(li.percentage ORDER BY li.views ASC) AS views,
group_concat(li.percentage ORDER BY li.percentage ASC)
FROM li GROUP BY client_id
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Can I concatenate multiple MySQL rows into one field?
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You can use GROUP_CONCAT:
SELECT person_id, GROUP_CONCAT(hobbies SEPARATOR ', ')
FROM peoples_hobbies
GROUP BY person_id;
As Ludwig stated in his comment, you can add the DISTINCT operator to avoid duplicates:
SELECT person_id, GROUP_CONCAT(D...