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Random record in ActiveRecord
...he first, all after are still sorted by id). If you need multiple randomly selected records you must use this approach multiple times or use the random order method provided by your database, i.e. Thing.order("RANDOM()").limit(100) for 100 randomly selected entries. (Be aware that it's RANDOM() in P...
How do I create a SQL table under a different schema?
...er 2008
1. Navigate to Security > Schemas
2. Right click on Schemas and select New Schema
3. Complete the details in the General tab for the new schema. Like, the schema name is "MySchema" and the schema owner is "Admin".
4. Add users to the schema as required and set their permissions:
5. Add an...
How do I set up NSZombieEnabled in Xcode 4?
...
⌥⌘R
(or click Menubar > Product > Scheme > Edit Scheme)
select the "Diagnostics" tab and click "Enable Zombie Objects":
This turns released objects into NSZombie instances that print console warnings when used again. This is a debugging aid that increases memory use (no objec...
Viewing complete strings while debugging in Eclipse
...ck on Details pane (the section where the string content is displayed) and select "Max Length..." popup menu. The same length applies to expression inspector popup and few other places.
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How to import existing Android project into Eclipse?
... import and existing Android project into my current Eclipse workspace. I select File->New->Android Project, which brings up the Android project dialog, I then select, "Create project from existing source", Location, Build Target and Finish.
...
In SQL, what's the difference between count(column) and count(*)?
...a values(null,1)
insert #bla values(1,null)
insert #bla values(null,null)
select count(*),count(id),count(id2)
from #bla
results
7 3 2
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Is there a “previous sibling” selector?
...
No, there is no "previous sibling" selector.
On a related note, ~ is for general successor sibling (meaning the element comes after this one, but not necessarily immediately after) and is a CSS3 selector. + is for next sibling and is CSS2.1.
See Adjacent sib...
JPA : How to convert a native query result set to POJO class collection
...e done with an entity.
For instance:
Query query = em.createNativeQuery("SELECT name,age FROM jedi_table", Jedi.class);
@SuppressWarnings("unchecked")
List<Jedi> items = (List<Jedi>) query.getResultList();
But in this case, Jedi, must be a mapped entity class.
An alternative to avoi...
How to convert timestamp to datetime in MySQL?
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SELECT from_unixtime( TIMESTAMP( "2011-12-01", "22:01:23.048" ) ) doesn't work. why? using v5.6
– Janus Troelsen
Feb 4 '14 at 18:44
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select and update database record with a single queryset
How do I run an update and select statements on the same queryset rather than having to do two queries:
- one to select the object
- and one to update the object
...