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SqlDataAdapter vs SqlDataReader
...nnection open until you are finished (don't forget to close it!).
Can typically only be iterated over once
Is not as useful for updating back to the database
On the other hand, it:
Only has one record in memory at a time rather than an entire result set (this can be HUGE)
Is about as fast as you c...
ALTER TABLE to add a composite primary key
I have a table called provider . I have three columns called person , place , thing . There can be duplicate persons, duplicate places, and duplicate things, but there can never be a dupicate person-place-thing combination.
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Set selected option of select box
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edited Jan 20 '19 at 10:47
João Pimentel Ferreira
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MySQL: #126 - Incorrect key file for table
... a ramdisk configured. You can temporarily comment out the ramdisk line to allow such operations if you can't increase the size of it.
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What is the difference between “def” and “val” to define a function
...gt; Int = {
val r = util.Random.nextInt
() => r
}
test()
// Int = -1049057402
test()
// Int = -1049057402 - same result
def test: () => Int = {
val r = util.Random.nextInt
() => r
}
test()
// Int = -240885810
test()
// Int = -1002157461 - new result
val evaluates when defined, ...
Installing specific package versions with pip
I'm trying to install version 1.2.2 of the MySQL_python adaptor, using a fresh virtualenv created with the --no-site-packages option. The current version shown in PyPi is 1.2.3 . Is there a way to install the older version? I found an article stating that this should do it:
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How to remove unreferenced blobs from my git repo
...and without further ado, may I present to you this useful command, "git-gc-all", guaranteed to remove all your git garbage until they might come up extra config variables:
git -c gc.reflogExpire=0 -c gc.reflogExpireUnreachable=0 -c gc.rerereresolved=0 -c gc.rerereunresolved=0 -c gc.pruneExpire=now ...
Pandas count(distinct) equivalent
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edited Jun 10 '15 at 17:24
LondonRob
46.9k2626 gold badges9797 silver badges139139 bronze badges
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Parallelize Bash script with maximum number of processes
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With GNU Parallel http://www.gnu.org/software/parallel/ you can write:
some-command | parallel do-something
GNU Parallel also supports running jobs on remote computers. This will run one per CPU core on the remote computers - even if ...
Most popular screen sizes/resolutions on Android phones [closed]
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Here is a list of almost all resolutions of tablets, with the most common ones in bold :
2560X1600
1366X768
1920X1200
1280X800
1280X768
1024X800
1024X768
1024X600
960X640
960X540
854X480
800X600
800X480
800X400
Happy designing .. ! :)
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