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How to create a HashMap with two keys (Key-Pair, Value)?
...mply use:
Map<Key, V> map = //...
and:
map.get(new Key(2, 5));
Table from Guava
Table<Integer, Integer, V> table = HashBasedTable.create();
//...
table.get(2, 5);
Table uses map of maps underneath.
N dimensions
Notice that special Key class is the only approach that scales to...
Design Pattern for Undo Engine
...e object is needed, you lookup the current definition of the object from a table. The table contains a linked list for each object that contains all the previous versions, along with information regarding which checkpoint they were active for.
Implementing undo/redo is simple: Do your action and es...
Are database triggers evil? [closed]
...
They are completely Global - they apply no matter what the context of the table activity;
They are stealthy; it's easy to forget they are there until they hurt you with unintended (and very mysterious) consequences.
This just means they need to be carefully used for the proper circumstances; whi...
Convert Unix timestamp into human readable date using MySQL
...
Use FROM_UNIXTIME():
SELECT
FROM_UNIXTIME(timestamp)
FROM
your_table;
See also: MySQL documentation on FROM_UNIXTIME().
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How do I check if a SQL Server text column is empty?
I am using SQL Server 2005. I have a table with a text column and I have many rows in the table where the value of this column is not null, but it is empty. Trying to compare against '' yields this response:
...
Why use a READ UNCOMMITTED isolation level?
... sense for reading data will never be modified. Trying to use that to read tables that would be written to means that you will in practice read something that gets rolled back. It's not just that you are reading data that's a few seconds old, but you ....................................................
Tools for JPEG optimization? [closed]
... tools I could find, including MozJPEG and jpegoptim that optimize Huffman tables, progressive scans, and (optionally) remove invisible metadata.
If you don't have a Mac, I also have a basic web interface that works on any platform.
...
Routing for custom ASP.NET MVC 404 Error page
...
Just add catch all route at the end of the routes table and display whatever page you want with it.
See: How can i make a catch all route to handle '404 page not found' queries for ASP.NET MVC?
shar...
Shortcuts in Objective-C to concatenate NSStrings
...ly as pleasant as just having a concatenation operator.
First, use an NSMutableString, which has an appendString method, removing some of the need for extra temp strings.
Second, use an NSArray to concatenate via the componentsJoinedByString method.
...
How can one print a size_t variable portably using the printf family?
...o print it using printf() . What format specifier do I use to print it portably?
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