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Real mouse position in canvas [duplicate]
...: evt.clientX - rect.left,
y: evt.clientY - rect.top
};
}
Just call it from your event with the event and canvas as arguments. It returns an object with x and y for the mouse positions.
As the mouse position you are getting is relative to the client window you'll have to subtract the po...
MySQL ON vs USING?
...l countries but just the cities starting with C or D (if any). (Plus towns called 'E')
– Roemer
Jun 12 at 18:04
...
What is the difference between single and double quotes in SQL?
...ur application code to be something other than what the column is actually called in the database. For example: PRODUCT.id would be more readable as product_id, so you use either of the following:
SELECT PRODUCT.id AS product_id
SELECT PRODUCT.id 'product_id'
Either works in Oracle, SQL Server,...
Change the selected value of a drop-down list with jQuery
...d a change event fire after changing the value of the dropbox, you need to call the change function after setting the value.
– tver3305
Jun 3 '15 at 10:25
...
How to use if statements in underscore.js templates?
...ce between "date is undefined" and "date is not defined". They should have called that error "No variable or global property exists with the name 'date'." The code you've proposed will still throw an exception if date doesn't exist at all. You really do need the typeof in this case, although it woul...
How do I assert equality on two classes without an equals method?
... all of the nodes in the graph implement "equal" and "hashcode", which basically make this method nearly useless. AssertJ's isEqualToComparingFieldByFieldRecursively is the one working perfectly in my case.
– John Zhang
Aug 10 '18 at 12:59
...
What is a proper naming convention for MySQL FKs?
... constraints. If a name is not given, InnoDB creates a unique name automatically.
In any case, this is the convention that I use:
fk_[referencing table name]_[referenced table name]_[referencing field name]
Example:
CREATE TABLE users(
user_id int,
name varchar(100)
);
CREATE ...
How do I retrieve an HTML element's actual width and height?
...e done certain DOM modifications to the element recently. You may have to call this code in a setTimeout call after you've modified the element.
– Dan Fabulich
Jan 19 '10 at 5:59
...
Difference between JSONObject and JSONArray
...hen dealing with JSON that begins with curly braces. A JSON object is typically used to contain key/value pairs related to one item.
For example: {"name": "item1", "description":"a JSON object"}
Of course, JSON arrays and objects may be nested inside one another. One common example of this is an ...
Rails :dependent => :destroy VS :dependent => :delete_all
...
The difference is with the callback.
The :delete_all is made directly in your application and deletes by SQL :
DELETE * FROM users where compagny_id = XXXX
With the :destroy, there is an instantiation of all of your children. So, if you can't destr...