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Immutable vs Mutable types
... changing what the variable refers to. A mutable type can change that way, and it can also change "in place".
Here is the difference.
x = something # immutable type
print x
func(x)
print x # prints the same thing
x = something # mutable type
print x
func(x)
print x # might print something differe...
MongoDB: Combine data from multiple collections into one..how?
...you can use as an _id.
For example, let's say you have a users collection and a comments collection and you want to have a new collection that has some user demographic info for each comment.
Let's say the users collection has the following fields:
_id
firstName
lastName
country
gender
age
And...
Passing A List Of Objects Into An MVC Controller Method Using jQuery Ajax
...et; set; }
}
There are two things I learned from this:
The contentType and dataType settings are absolutely necessary in the ajax() function. It won't work if they are missing. I found this out after much trial and error.
To pass in an array of objects to an MVC controller method, simply use th...
Are there conventions on how to name resources?
Are there conventions how to name resources in Android? For example, buttons, textViews, menus, etc.
15 Answers
...
In CMake, how can I test if the compiler is Clang?
We have a set of cross-platform CMake build scripts , and we support building with Visual C++ and GCC .
5 Answers
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Understanding PrimeFaces process/update and JSF f:ajax execute/render attributes
What exactly are process and update in PrimeFaces p:commandXxx components and execute and render in f:ajax tag?
...
MySQL Cannot Add Foreign Key Constraint
...ing to add Foreign Key constraints to my database as a project requirement and it worked the first time or two on different tables, but I have two tables on which I get an error when trying to add the Foreign Key Constraints.
The error message that I get is:
...
On delete cascade with doctrine2
...a simple example in order to learn how to delete a row from a parent table and automatically delete the matching rows in the child table using Doctrine2.
...
PHP - find entry by object property from an array of objects
...;ID) {
$item = $struct;
break;
}
}
See this question and subsequent answers for more information on the latter - Reference PHP array by multiple indexes
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How to add an auto-incrementing primary key to an existing table, in PostgreSQL?
...e with existing data. Is there a way to add a primary key without deleting and re-creating the table?
4 Answers
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