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What is the most efficient/elegant way to parse a flat table into a tree?
...id, descendant_id) VALUES
(1,1), (1,2), (1,4), (1,6),
(2,2), (2,4),
(3,3), (3,5),
(4,4),
(5,5),
(6,6);
Now you can get a tree starting at node 1 like this:
SELECT f.*
FROM FlatTable f
JOIN ClosureTable a ON (f.id = a.descendant_id)
WHERE a.ancestor_id = 1;
The output (in MySQL c...
Python syntax for “if a or b or c but not all of them”
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238
If you mean a minimal form, go with this:
if (not a or not b or not c) and (a or b or c):
Wh...
if, elif, else statement issues in Bash
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U. Windl
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answered Apr 16 '13 at 10:34
fedorqui 'SO stop harming'fedorqu...
Show pending migrations in rails
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rake db:migrate:status (Rails 3 to 5) or rails db:migrate:status (Rails 5) will accomplish this. See this commit.
up means the migration has been run. down means the migration has not been run.
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Remove empty strings from a list of strings
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1203
I would use filter:
str_list = filter(None, str_list)
str_list = filter(bool, str_list)
str_lis...
Is sizeof(bool) defined in the C++ language standard?
...ntation defined, and the standard puts notable emphasis on this fact.
§5.3.3/1, abridged:
sizeof(char), sizeof(signed char) and sizeof(unsigned char) are 1; the result of sizeof applied to any other fundamental type is implementation-defined. [Note: in particular, sizeof(bool) and sizeof(wchar...
What is the difference between tinyint, smallint, mediumint, bigint and int in MySQL?
...8 to 127 0 to 255
smallint | 2 bytes -32768 to 32767 0 to 65535
mediumint | 3 bytes -8388608 to 8388607 0 to 16777215
int/integer | 4 bytes -2147483648 to 2147483647 0 to 4294967295
bigi...
PHP Difference between array() and []
... |
edited May 18 '16 at 5:35
e2-e4
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answered Jul ...
Using System.Dynamic in Roslyn
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AlbertoAlberto
13.2k88 gold badges4040 silver badges4949 bronze badges
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