大约有 47,000 项符合查询结果（耗时：0.0615秒） [XML]
How exactly does a generator comprehension work?
... # notice it's a generator object
<generator object <genexpr> at 0x7f2ad75f89e0>
>>> len(filtered_gen) # So technically, it has no length
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: object of type 'generator' has no len()
>...
Simple way to calculate median with MySQL
...um+1 as `row_number`, @total_rows:=@rownum
FROM data d, (SELECT @rownum:=0) r
WHERE d.val is NOT NULL
-- put some where clause here
ORDER BY d.val
) as dd
WHERE dd.row_number IN ( FLOOR((@total_rows+1)/2), FLOOR((@total_rows+2)/2) );
Steve Cohen points out, that after the first pass, @rown...
If list index exists, do X
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edited Dec 12 '16 at 0:03
Dimitris Fasarakis Hilliard
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How do I query using fields inside the new PostgreSQL JSON datatype?
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180
Postgres 9.2
I quote Andrew Dunstan on the pgsql-hackers list:
At some stage there will pos...
Can't connect to local MySQL server through socket '/tmp/mysql.sock' (2)
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edited Feb 15 '18 at 20:12
user664833
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answ...
iOS: Compare two dates
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210
According to Apple documentation of NSDate compare:
Returns an NSComparisonResult value that...
Pickle or json?
...
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edited Sep 30 '18 at 16:41
Daniel Heilper
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Formatting Numbers by padding with leading zeros in SQL Server
We have an old SQL table that was used by SQL Server 2000 for close to 10 years.
13 Answers
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Clicking the text to select corresponding radio button
... <label for="349">Abe</label>
<br>
<input id="350" type="radio" value="2" name="question1">
<label for="350">Andrew</label>
<br>
<input id="351" type="radio" value="3" name="question1">
<label for="351">Andre</label>
&l...
How do I verify/check/test/validate my SSH passphrase?
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edited Jun 6 at 21:40
Peter Mortensen
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