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SQL - many-to-many table primary key
...er. The surrogate is a waste of space.
You won't need indexes on the individual columns since the table should only ever be used to join the two referenced tables together.
That comment you refer to in the question is not worth the electrons it uses, in my opinion. It sounds like the author thinks...
Why is git push gerrit HEAD:refs/for/master used instead of git push origin master
...(in the diagram, "Pending Changes"). Gerrit doesn't actually have a branch called <BRANCH>; it lies to the git client.
Internally, Gerrit has its own implementation for the Git and SSH stacks. This allows it to provide the "magical" refs/for/<BRANCH> refs.
When a push request is r...
Mongodb Explain for Aggregation framework
...rations
explain:true
db.collection.aggregate([
{ $project : { "Tags._id" : 1 }},
{ $unwind : "$Tags" },
{ $match: {$or: [{"Tags._id":"tag1"},{"Tags._id":"tag2"}]}},
{ $group: {
_id : "$_id",
count: { $sum:1 }
}},
{$sort: {"count":-1}}
],
{
explain:...
Reference list item by index within Django template?
...ave an array in which I'm not sure of the index of my desired value {% for id in article_details.heading.contents.article_ids %} {% if id.type == 'DOI' %} {{ article_details.heading.contents.article_ids.forloop.counter0.value }} {% endif %} {% endfor %}
–...
Rails filtering array of objects by attribute value
...
As @Vik's solution is pretty much ideal, I'll just add that in binary cases, you could use a 'partition' function to make things sweet. ruby-doc.org/core-1.9.3/Enumerable.html#method-i-partition
– Vlad
Jun 20 '16 at 21:...
MySQL Cannot drop index needed in a foreign key constraint
...the index: ALTER TABLE mytable ADD CONSTRAINT mytable_ibfk_1 FOREIGN KEY (AID) REFERENCES mytable_a (ID) ON DELETE CASCADE;
– laffuste
Feb 11 '14 at 7:49
8
...
SQL/mysql - Select distinct/UNIQUE but return all columns?
...ue.. Any other aggregate function available to address boolean – signonsridhar 6 mins ago. Sum(dynamic) changed false to 1
– signonsridhar
Aug 22 '16 at 2:00
...
Is there any way to use a numeric type as an object key?
...finition of property. Eg, myArray.hasOwnProperty("1") yields true. Semantically, this property can also be considered an "element" by virtue of having a numeric key, but there is nothing further that distinguishes an array "element" from an array property. Read the spec. If you still disagree, kind...
List of zeros in python [duplicate]
...tertools.repeat and [0] * n will create lists whose elements refer to same id. This is not a problem with immutable objects like integers or strings but if you try to create list of mutable objects like a list of lists ([[]] * n) then all the elements will refer to the same object.
a = [[]] * 10
a...
create a trusted self-signed SSL cert for localhost (for use with Express/Node)
...nd it will work. Chrome doesn't:
Step 1. in your backend, create a folder called security. we will work inside it.
Step 2. create a request config file named req.cnf with the following content (credit goes to: @Anshul)
req.cnf :
[req]
distinguished_name = req_distinguished_name
x509_extensions =...