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Best way to store time (hh:mm) in a database
...t a glance and performing calculations on them are straightforward.
E.g.
SELECT DATEDIFF(MINUTE, event_start, event_end)
ISO8601 date standard
If using SQLite then you don't have this, so instead use a Text field and store it in ISO8601 format eg.
"2013-01-27T12:30:00+0000"
Notes:
This use...
Write a program to find 100 largest numbers out of an array of 1 billion numbers
...ulate this probability. For example, lets assume the numbers were randomly selected uniformly from {0, 1}, the expected value of (i-K)th number (out of i numbers) is (i-k)/i, and chance of a random variable being larger than this value is 1-[(i-k)/i] = k/i.
Thus, the expected number of insertions ...
VS2012 return to a normal TFS checkin window?
...n the Pending Changes filter is applied, all or some of the files could be selected and right clicked and then there is an option to do the check in. That command takes directly to the Team Explorer in Pending Changes view. See below...
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Why use the params keyword?
...
You could also use return args.Select(x => x + 2).Sum();
– bbvg
Aug 22 '17 at 21:07
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How to speed up insertion performance in PostgreSQL
...rypto module) is (a lot) faster than uuid_generate_v4()
=# explain analyze select uuid_generate_v4(),* from generate_series(1,10000);
QUERY PLAN
---------------------------------------------------------------------------------------------------...
How do I create a unique constraint that also allows nulls?
...dy found separately in other, properly defined columns. It should never be selected or used.
So, my story is that this is not a surrogate NULL, and I'm sticking to it! Since we don't actually want the non-NULL value for any purpose other than to trick the UNIQUE index to ignore NULLs, our use case ...
How to map a composite key with JPA and Hibernate?
... way you write queries (making them more or less verbose):
with IdClass
select t.levelStation from Time t
with EmbeddedId
select t.timePK.levelStation from Time t
References
JPA 1.0 specification
Section 2.1.4 "Primary Keys and Entity Identity"
Section 9.1.14 "EmbeddedId Annotation"
Sect...
How can I tell if my server is serving GZipped content?
...erested). You can tell using Developer Tools (F12). Go to the Network tab, select the file you want to examine and then look at the Headers tab on the right. If you are gzipped, then you will see that in the Content-Encoding.
In this example, slider.jpg is indeed being gzipped.
Compare that to t...
How to store arrays in MySQL?
... retrieve a person and all of their fruit you can do something like this:
SELECT p.*, f.*
FROM person p
INNER JOIN person_fruit pf
ON pf.person_id = p.id
INNER JOIN fruits f
ON f.fruit_name = pf.fruit_name
share
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How to specify font attributes for all elements on an html web page?
...es use: *,:before,:after{font-family:inherit;} if you must use a universal selector, use inheritance instead.
– darcher
Jun 5 '15 at 16:15
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