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Finding duplicate values in MySQL
I have a table with a varchar column, and I would like to find all the records that have duplicate values in this column. What is the best query I can use to find the duplicates?
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Why doesn't Objective-C support private methods?
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The answer is... well... simple. Simplicity and consistency, in fact.
Objective-C is purely dynamic at the moment of method dispatch. In particular, every method dispatch goes through the exact same dynamic method resolution point as every other method dispatch. At...
EC2 instance has no public DNS
...as not the one who set it up. Some of the instances show a public dns name and others have a blank public DNS. I want to be able to connect to the instances that have a blank public DNS. I have not been able to figure out why these show up as blank.
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Recommendations of Python REST (web services) framework? [closed]
...use on the serverside to write your own RESTful APIs? Preferably with pros and cons.
16 Answers
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What is “android:allowBackup”?
...e, either open the lint warnings view, where you can select the lint error and see a longer explanation, or invoke the quick fix (Ctrl-1) on the error line, and one of the suggestions is "Explain this issue", which will also pop up a fuller explanation. If you are not using Eclipse, you can generate...
Understanding offsetWidth, clientWidth, scrollWidth and -Height, respectively
... on StackOverflow regarding offsetWidth / clientWidth / scrollWidth (and -Height , respectively), but none give comprehensive explanation of what those values are.
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How to validate an email address in PHP
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The easiest and safest way to check whether an email address is well-formed is to use the filter_var() function:
if (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
// invalid emailaddress
}
Additionally you can check whether the do...
SQL Server - Create a copy of a database table and place it in the same database?
...is will create a new table ABC_1 that has the same column structure as ABC and contains the same data. Constraints (e.g. keys, default values), however, are -not- copied.
You can run this query multiple times with a different table name each time.
If you don't need to copy the data, only to cre...
Visual Studio 2013 doesn't discover unit tests
...isual studio 2013 that is composed by one web project, one library project and one unit test project. When I open the solution and try to run the unit tests they are not discover by visual studio. To run the tests I try to go to the menu and choose Test -> Run -> Run all tests or by opening the test...
How to speed up insertion performance in PostgreSQL
...n the PostgreSQL manual, depesz's excellent-as-usual article on the topic, and this SO question.
(Note that this answer is about bulk-loading data into an existing DB or to create a new one. If you're interested DB restore performance with pg_restore or psql execution of pg_dump output, much of thi...