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Weird Integer boxing in Java
... section 5.1.7:
If the value p being boxed is true,
false, a byte, a char in the range
\u0000 to \u007f, or an int or short
number between -128 and 127, then let
r1 and r2 be the results of any two
boxing conversions of p. It is always
the case that r1 == r2.
The discussion goes on...
Rails 3: Get Random Record
...You can use the following trick on an indexed column (PostgreSQL syntax):
select *
from my_table
where id >= trunc(
random() * (select max(id) from my_table) + 1
)
order by id
limit 1;
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Declaring an unsigned int in Java
...
Use char for 16 bit unsigned integers.
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How can I add an item to a SelectList in ASP.net MVC
Basically I am looking to insert an item at the beginning of a SelectList with the default value of 0 and the Text Value of " -- Select One --"
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How to get distinct values for non-key column fields in Laravel?
...lder you can do it this way:
$users = DB::table('users')
->select('id','name', 'email')
->groupBy('name')
->get();
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ASP.NET Identity reset password
...
Thank you for your answer. It works like a charm for me.
– Thomas.Benz
Mar 16 '17 at 13:43
4
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How to subtract 30 days from the current datetime in mysql?
...
SELECT * FROM table
WHERE exec_datetime BETWEEN DATE_SUB(NOW(), INTERVAL 30 DAY) AND NOW();
http://dev.mysql.com/doc/refman/5.5/en/date-and-time-functions.html#function_date-add
...
Powershell v3 Invoke-WebRequest HTTPS error
...s): "The remote server returned an error: (406) Not Acceptable." At line:4 char:1 + $wc.DownloadString($url) + ~~~~~~~~~~~~~~~~~~~~~~~~ + CategoryInfo : NotSpecified: (:) [], MethodInvocationException + FullyQualifiedErrorId : WebException
– floyd
...
How to generate an entity-relationship (ER) diagram using Oracle SQL Developer
... as follows:
Click File → Data Modeler → Import → Data Dictionary.
Select a DB connection (add one if none).
Click Next.
Check one or more schema names.
Click Next.
Check one or more objects to import.
Click Next.
Click Finish.
The ERD is displayed.
Export the diagram as follows:
Click ...
Selecting only numeric columns from a data frame
...traightforward, and robust to use on database-back-ended tibbles:
dplyr::select_if(x, is.numeric)
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