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In SQL, what's the difference between count(column) and count(*)?
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Just curious: if you have a row with all NULLs, would count(*) still count it, or is just count(column) for all columns?
– Joel Coehoorn
Sep 12 '08 at 15:29
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Dump Mongo Collection into JSON format
...ut.json
WARNING
mongoimport and mongoexport do not reliably preserve all rich BSON data types because JSON can only represent a subset of the types supported by BSON. As a result, data exported or imported with these tools may lose some measure of fidelity.
Also, http://bsonspec.org/
BSO...
Collapsing Sidebar with Bootstrap
...le should help to get you started.
https://codeply.com/p/esYgHWB2zJ
Basically you need to wrap the layout in an outer div, and use media queries to toggle the layout on smaller screens.
/* collapsed sidebar styles */
@media screen and (max-width: 767px) {
.row-offcanvas {
position: relative...
How can I get column names from a table in SQL Server?
I want to query the name of all columns of a table. I found how to do this in:
20 Answers
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Update ViewPager dynamically?
...t is best to deal solely with getItem() and not touch instantiateItem() at all. The instantiateItem()-destroyItem()-isViewFromObject() interface on PagerAdapter is a lower-level interface that FragmentPagerAdapter uses to implement the much simpler getItem() interface.
Before getting into this, I s...
Is a GUID unique 100% of the time?
...ge that the probability of the same number being
generated twice is very small. For
example, consider the observable
universe, which contains about 5×1022
stars; every star could then have
6.8×1015 universally unique GUIDs.
From Wikipedia.
These are some good articles on how a GUID is made (for ...
Awaiting multiple Tasks with different results
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After you use WhenAll, you can pull the results out individually with await:
var catTask = FeedCat();
var houseTask = SellHouse();
var carTask = BuyCar();
await Task.WhenAll(catTask, houseTask, carTask);
var cat = await catTask;
var house =...
Constructing pandas DataFrame from values in variables gives “ValueError: If using all scalar values
...ipulate it to be index=[100], which works. Q: Isn't Index supposed to logically ordered incrementally, why does python allow Index manipulation?
– Sumanth Lazarus
Aug 2 '19 at 6:08
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jQuery see if any or no checkboxes are selected
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JQuery .is will test all specified elements and return true if at least one of them matches selector:
if ($(":checkbox[name='choices']", form).is(":checked"))
{
// one or more checked
}
else
{
// nothing checked
}
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ANTLR: Is there a simple example?
...r, and evaluator using ANTLR4.
You first create a grammar. Below is a small grammar that you can use to evaluate expressions that are built using the 4 basic math operators: +, -, * and /. You can also group expressions using parenthesis.
Note that this grammar is just a very basic one: it does ...