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Correct use of transactions in SQL Server
..._ABORT ON -- Turns on rollback if T-SQL statement raises a run-time error.
SELECT * FROM T; -- Check before.
BEGIN TRAN
INSERT INTO T VALUES ('A');
INSERT INTO T VALUES ('B');
INSERT INTO T VALUES ('B');
INSERT INTO T VALUES ('C');
COMMIT TRAN
SELECT * FROM T; -- Check after.
DELETE ...
Haskell Type vs Data Constructor
...to consider the difference between a concrete type (examples include Int, [Char] and Maybe Bool) which is a type that can be assigned to a value in your program, and a type constructor function which you need to feed a type to be able to be assigned to a value. A value can never be of type "list", b...
android pick images from gallery
....ACTION_GET_CONTENT);
startActivityForResult(Intent.createChooser(intent, "Select Picture"), PICK_IMAGE);
Don't forget also to create the constant PICK_IMAGE, so you can recognize when the user comes back from the image gallery Activity:
public static final int PICK_IMAGE = 1;
@Override
public v...
Is there a rule-of-thumb for how to divide a dataset into training and validation sets?
...o training and validation (again, 80/20 is a fair split).
Subsample random selections of your training data, train the classifier with this, and record the performance on the validation set
Try a series of runs with different amounts of training data: randomly sample 20% of it, say, 10 times and obs...
How to split last commit into two in Git
...do and unstage all of the changes from the last commit:
git reset HEAD^
Selectively stage the first round of changes:
git add -p
Commit:
git commit
Commit the rest of the changes:
git commit -a
(In either step, if you undid a commit that added a brand new file and want to add this to the...
What is a NullReferenceException, and how do I fix it?
... to find out where the reference is or isn't set, right-click its name and select "Find All References". You can then place a breakpoint at every found location and run your program with the debugger attached. Every time the debugger breaks on such a breakpoint, you need to determine whether you exp...
Where can I locate themes for VS2012
... in another machine and at first it did not work. It turned out that I had selected the key name from this response by double clicking it, then copied it, then pasted it in regedit. Well, by doing so I had inadvertently created the key with a trailing space in the name! And hence it did not work.
S...
How to use conditional breakpoint in Eclipse?
...t editor margin or in the Breakpoints
view in the Debug perspective, and select the breakpoint’s properties.
In the dialog box, check Enable Condition, and enter an arbitrary Java
condition, such as list.size()==0. Now, each time the breakpoint is
reached, the expression is evaluated in th...
INNER JOIN vs LEFT JOIN performance in SQL Server
...(ID, Name) VALUES (4, 'Four')
INSERT #Test2 (ID, Name) VALUES (5, 'Five')
SELECT *
FROM #Test1 t1
INNER JOIN #Test2 t2
ON t2.Name = t1.Name
SELECT *
FROM #Test1 t1
LEFT JOIN #Test2 t2
ON t2.Name = t1.Name
DROP TABLE #Test1
DROP TABLE #Test2
If you run this and view the execution plan, you'll se...
Visual Studio: Make view code default
...
Right-click on a file and select "Open With..."
Select "CSharp Editor" and then click "Set as Default".
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