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Database development mistakes made by application developers [closed]
...vely easy one but still it happens all the time. Foreign keys should have indexes on them. If you're using a field in a WHERE you should (probably) have an index on it. Such indexes should often cover multiple columns based on the queries you need to execute.
2. Not enforcing referential integri...
Extract elements of list at odd positions
...efault (0) would be used. So the first element (at position 0, because the indexes are 0-based) would be selected. In this case the second element will be selected.
Because the second element is omitted, the default is being used (the end of the list). So the list is being iterated from the second ...
How to apply a function to two columns of Pandas dataframe
...unction f, rewrite the function to accept a pandas Series object, and then index the Series to get the values needed.
In [49]: df
Out[49]:
0 1
0 1.000000 0.000000
1 -0.494375 0.570994
2 1.000000 0.000000
3 1.876360 -0.229738
4 1.000000 0.000000
In [50]: def f(x):
...
How to change value of object which is inside an array using JavaScript or jQuery?
...
It is quite simple
Find the index of the object using findIndex method.
Store the index in variable.
Do a simple update like this: yourArray[indexThatyouFind]
//Initailize array of objects.
let myArray = [
{id: 0, name: "Jhon"},
{id: 1, nam...
pandas: multiple conditions while indexing data frame - unexpected behavior
...tackoverflow.com%2fquestions%2f22591174%2fpandas-multiple-conditions-while-indexing-data-frame-unexpected-behavior%23new-answer', 'question_page');
}
);
Post as a guest
...
Array vs. Object efficiency in JavaScript
...sically an array with holes in it, because every array does have continous indexing. It's slower than arrays without holes. But iterating manually through the array is even slower (mostly).
This is an object:
var a3 = {};
a3[29938] = "a";
a3[32994] = "b";
Here is a performance test of three poss...
How do I implement IEnumerable
...ect> mylist = new List<MyObject>();
public MyObject this[int index]
{
get { return mylist[index]; }
set { mylist.Insert(index, value); }
}
public IEnumerator<MyObject> GetEnumerator()
{
return mylist.GetEnumerator();
}
IE...
What is difference between Collection.stream().forEach() and Collection.forEach()?
... for:each 53 171 1262 11164 111005
for with index 39 112 920 8577 89212
iterable.stream.forEach 255 324 1030 8519 88419
If you repeat the experiment, I posted the full source code. Please do edit this answer and add you results with a notation ...
allowDefinition='MachineToApplication' error when publishing from VS2010 (but only after a previous
...
Yes... adding rmdir /S /Q "$(ProjectDir)\obj" to the post build section as per the Microsoft Ticket solved the problem!
– Leniel Maccaferri
May 3 '12 at 21:16
...
How to go about formatting 1200 to 1.2k in java
...tring result = new DecimalFormat("##0E0").format(number);
Integer index = Character.getNumericValue(result.charAt(result.length() - 1)) / 3;
result = result.replaceAll("E[0-9]", METRIC_PREFIXES[index]);
while (result.length() > MAX_LENGTH || TRAILING_DECIMAL_POINT.matche...