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How to use GROUP_CONCAT in a CONCAT in MySQL
...
Try:
CREATE TABLE test (
ID INTEGER,
NAME VARCHAR (50),
VALUE INTEGER
);
INSERT INTO test VALUES (1, 'A', 4);
INSERT INTO test VALUES (1, 'A', 5);
INSERT INTO test VALUES (1, 'B', 8);
INSERT INTO test VALUES (2, 'C', 9);
SELECT ID, GRO...
What is the difference between \r and \n?
... C has several escape sequences for representing control codes:
\a (for alert) which rings the teletype bell or makes the terminal beep
\f (for form feed) which moves to the beginning of the next page
\t (for tab) which moves the print head to the next horizontal tab position
(This list is inte...
Remove duplicate dict in list in Python
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@alexis I made a few tests and you are indeed right. If a lot of keys are added in between and removed later, then that could be the case. Thanks a lot for your comment.
– jcollado
Feb 24 '12 at 15:53
...
Where in a virtualenv does the custom code go?
... you have multiple applications using the same virtualenv. Or, you may be testing an application with a virtualenv that will later be deployed with a system Python. Or, you may be packaging up a standalone app where it might make sense to have the virtualenv directory located somewhere within the ...
what is the best way to convert a json formatted key value pair to ruby hash with symbol as key?
...n/deserialization, which also preserves the format of the key:
YAML.load({test: {'test' => { ':test' => 5}}}.to_yaml)
=> {:test=>{"test"=>{":test"=>5}}}
Benefit of this approach it seems like a format that is better suited for REST services...
...
How do you produce a .d.ts “typings” definition file from an existing JavaScript library?
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--allowJs with --declaration options can't be combined (tested in TypeScript 1.8 and 2.0). If I try, I get: error TS5053: Option 'allowJs' cannot be specified with option 'declaration'
– Alexey
Sep 27 '16 at 7:52
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What does send() do in Ruby?
...ibility checks, so that you can call private methods, too (useful for unit testing).
If there is really no variable before send, that means that the global Object is used:
send :to_s # "main"
send :class # Object
s...
How to trim a string in SQL Server before 2017?
...this example, Space, tab, LF and CR characters are being trimmed:
Declare @Test nvarchar(50) = Concat (' ', char(9), char(13), char(10), ' ', 'TEST', ' ', char(9), char(10), char(13),' ', 'Test', ' ', char(9), ' ', char(9), char(13), ' ')
DECLARE @TrimPattern nvarchar(max) = '%[^ ' + char(9) + char(...
Python assigning multiple variables to same value? list behavior
...>>> a
1
>>> b
2
>>> c
3
>>> a,b,c = ({'test':'a'},{'test':'b'},{'test':'c'})
>>> a
{'test': 'a'}
>>> b
{'test': 'b'}
>>> c
{'test': 'c'}
>>>
share
...
Rank function in MySQL
...ows the variable initialization without requiring a separate SET command.
Test case:
CREATE TABLE person (id int, first_name varchar(20), age int, gender char(1));
INSERT INTO person VALUES (1, 'Bob', 25, 'M');
INSERT INTO person VALUES (2, 'Jane', 20, 'F');
INSERT INTO person VALUES (3, 'Jack', ...