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MySQL pagination without double-querying?
...ossible results before applying the limits. This can't be satisfied by an index because it actually fetches the data.
If you take the two queries approach, the first one only fetching COUNT(*) and not actually fetching and actual data, this can be satisfied much more quickly because it can usually...
json.net has key method?
...liamT.Mallard In C# 6, you can simplify that by using the null-conditional index operator: myJObject["level1property"]?["level2property"].
– svick
Jan 4 '17 at 19:45
...
Is there a way to measure how sorted a list is?
...r of inversions.
The number of inversions is the number of pairs (a,b) st index of a < b AND b << a. For these purposes << represents whatever ordering relation you choose for your particular sort.
A fully sorted list has no inversions, and a completely reversed list has the maximum...
I want to copy table contained from one database and insert onto another database table
...
This does not copy things such as index. It merely creates a table based on a set of tuples. You probably don't want to do this.
– BenMQ
Aug 26 '14 at 3:59
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How to iterate through all git branches using bash script
...C my_callback -c 1 < <( get_branches )
example:
my_callback () {
INDEX=${1}
BRANCH=${2}
echo "${INDEX} ${BRANCH}"
}
get_branches () {
git branch --all --format='%(refname:short)'
}
# mapfile -t -C my_callback -c 1 BRANCHES < <( get_branches ) # if you want the branches that wer...
Insertion Sort vs. Selection Sort
...
Both insertion sort and selection sort have an outer loop (over every index), and an inner loop (over a subset of indices). Each pass of the inner loop expands the sorted region by one element, at the expense of the unsorted region, until it runs out of unsorted elements.
The difference is in...
Is there a C++ gdb GUI for Linux? [closed]
...e tool becomes a nice experience.
The CDT tooling provides a decent C/C++ indexer that allows you to quickly find references to methods in your code base. It also provides a nice macro expansion tool and limited refactoring support.
With regards to support for debugging, CDT is able to do everyth...
In Python, how do I read the exif data for an image?
...n('img.jpg')
exif_data = img._getexif()
This should give you a dictionary indexed by EXIF numeric tags. If you want the dictionary indexed by the actual EXIF tag name strings, try something like:
import PIL.ExifTags
exif = {
PIL.ExifTags.TAGS[k]: v
for k, v in img._getexif().items()
if...
What are the complexity guarantees of the standard containers?
... O(1) (amortized)
v.insert(iterator, value) Insert value at the position indexed by iterator. O(n)
v.pop_back() Remove value from end. O(1)
v.assign(begin, end) Clear the container and copy in the elements from begin to e...
Show MySQL host via SQL Command
...e parts:
-- delivers the "remote_host" e.g. "localhost"
SELECT SUBSTRING_INDEX(USER(), '@', -1)
-- delivers the user-name e.g. "myuser"
SELECT SUBSTRING_INDEX(USER(), '@', 1)
if you are conneting via ip address you will get the ipadress instead of the hostname.
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