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What does “Object reference not set to an instance of an object” mean? [duplicate]
...es are primitives such as integers and booleans or structures (and can be identified because they inherit from System.ValueType). Boolean variables, when declared, have a default value:
bool mybool;
//mybool == false
Reference types, when declared, do not have a default value:
class ExampleClas...
MySQL “between” clause not inclusive?
...nce by using >= and < instead of between.
– David Harkness
Mar 20 '12 at 0:42
113
You will ...
Easiest way to rename a model using Django/South?
...rename_foo_to_bar --empty
(Update 2: try --auto instead of --empty to avoid the warning below. Thanks to @KFB for the tip.)
If you're using an older version of south, you'll need startmigration instead of schemamigration.
Then manually edit the migration file to look like this:
class Migration...
How to set a default value with Html.TextBoxFor?
...e Html.TextBoxFor method, my first guess was to try the following which did not work:
12 Answers
...
Rake just one migration
...and on what Ryan says, if the table has been dropped from the database outside of Rails, rake db:migrate:up VERSION=my_version may do nothing, because the schema_migrations table still says it is has been run. In the same situation rake db:migrate:redo VERSION=my_version may fail because it cannot d...
What to gitignore from the .idea folder?
... to add and what to exclude from our Git repository. Clearly some files inside the .idea folder are meant to be version controlled like the external library settings ( jsLibraryMappings.xml ) but others will probably change very often and are developer-specific (e.g., workspace.xml ).
...
Android Gallery on Android 4.4 (KitKat) returns different URI for Intent.ACTION_GET_CONTENT
... startActivityForResult(intent, GALLERY_KITKAT_INTENT_CALLED);
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (resultCode != Activity.RESULT_OK) return;
if (null == data) return;
U...
Dialog to pick image from gallery or from camera
...allery:
Intent pickPhoto = new Intent(Intent.ACTION_PICK,
android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
startActivityForResult(pickPhoto , 1);//one can be replaced with any action code
onActivityResult code:
protected void onActivityResult(int requestCode, int result...
Count table rows
...r when I use name of indexed column instead of * ? Like this: SELECT COUNT(id) FROM tablename
– user1810543
Nov 8 '12 at 21:01
1
...
RabbitMQ / AMQP: single queue, multiple consumers for same message?
...ot if the consumers are on the same queue. From RabbitMQ's AMQP Concepts guide:
it is important to understand that, in AMQP 0-9-1, messages are load balanced between consumers.
This seems to imply that round-robin behavior within a queue is a given, and not configurable. Ie, separate queues ar...