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MongoDB Aggregation: How to get total records count?
... { $group: { _id: null, count: { $sum: 1 } } }
] ).map(function(record, index){
print(index);
});
The aggregate will return the array so just loop it and get the final index .
And other way of doing it is:
var count = 0 ;
db.collection.aggregate([
{ $match : { score : { $gt : 70, $lt...
MySQL Cannot Add Foreign Key Constraint
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mysql> create unique index index_bar_id on foos(bar_id); ... mysql> alter table foos add constraint index_bar_id foreign key (bar_id) references bars (id); sixarm.com/about/…
– CookieCoder
Dec 17 ...
How to overlay one div over another div
...ght: 100%;
position: absolute;
top: 0;
left: 0;
}
#infoi {
z-index: 10;
}
<div id="container">
<div id="navi">a</div>
<div id="infoi">
<img src="https://appharbor.com/assets/images/stackoverflow-logo.png" height="20" width="32" />b
</div...
Disable all table constraints in Oracle
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Primary keys cannot be disabled on index-organized tables. You can handle these by adding AND NOT (t.iot_type IS NOT NULL AND c.constraint_type = 'P') to the first code segment.
– Andrew Miller
May 7 '15 at 15:15
...
Insert the carriage return character in vim
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Type: ctrl-v ctrl-m
On Windows Use: ctrl-q ctrl-m
Ctrl-V tells vi that the next character typed should be inserted literally and ctrl-m is the keystroke for a carriage return.
share
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How to delete an element from an array in C#
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If you want to remove all instances of 4 without needing to know the index:
LINQ: (.NET Framework 3.5)
int[] numbers = { 1, 3, 4, 9, 2 };
int numToRemove = 4;
numbers = numbers.Where(val => val != numToRemove).ToArray();
Non-LINQ: (.NET Framework 2.0)
static bool isNotFour(int n)
{
...
In Python, when to use a Dictionary, List or Set?
... and x not in l
l[i], l[i:j], l[i:j:k]
len(l), min(l), max(l)
l.count(x)
l.index(x[, i[, j]]) - index of the 1st occurrence of x in l (at or after i and before j indeces)
A list also implements all of the mutable sequence operations:
l[i] = x - item i of l is replaced by x
l[i:j] = t - slice of ...
Postgres NOT in array
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Note that the ANY/ALL operators will not work with array indexes. If indexes are in mind:
SELECT COUNT(*) FROM "messages" WHERE 3 && recipient_ids
and the negative:
SELECT COUNT(*) FROM "messages" WHERE NOT (3 && recipient_ids)
An index can then be created lik...
How can I access and process nested objects, arrays or JSON?
...const value = arr[5]; // arr.5 would be a syntax error
// property name / index as variable
const x = 5;
const value = arr[x];
Wait... what about JSON?
JSON is a textual representation of data, just like XML, YAML, CSV, and others. To work with such data, it first has to be converted to JavaScri...
Starting python debugger automatically on error
This is a question I have wondered about for quite some time, yet I have never found a suitable solution. If I run a script and I come across, let's say an IndexError, python prints the line, location and quick description of the error and exits. Is it possible to automatically start pdb when an err...