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How do I include related model fields using Django Rest Framework?
...ializers.ModelSerializer):
teachers = TeacherSerializer(source='teacher_set')
class Meta:
model = Classroom
Note that we use the source argument on the serializer field to specify the attribute to use as the source of the field. We could drop the source argument by instead making...
Setting variable to NULL after free
... int *nPtr=NULL;. Now, I would agree that this would be redundant, with a malloc following right in the next line. However, if there is code between the declaration and the first initialization, somebody might start using the variable even though it has no value yet. If you null-initialize, you get ...
Disable submit button when form invalid with AngularJS
...
+1 Coincidentally, I was just reading this great post of yours: benlesh.com/2012/11/angular-js-form-validation.html
– Ben
May 15 '14 at 17:48
...
How can I run MongoDB as a Windows service?
...r several hours, I finally did it.
Make sure that you added the <MONGODB_PATH>\bin directory to the system variable PATH
First I executed this command:
D:\mongodb\bin>mongod --remove
Then I executed this command after opening command prompt as administrator:
D:\mongodb\bin>mongod --dbpa...
How to ignore xargs commands if stdin input is empty?
... -L <#lines>, -n <#args>, -i, and -I <string>:
ls /empty_dir/ | xargs -n10 chown root # chown executed every 10 args or fewer
ls /empty_dir/ | xargs -L10 chown root # chown executed every 10 lines or fewer
ls /empty_dir/ | xargs -i cp {} {}.bak # every {} is replaced with the args...
Shall we always use [unowned self] inside closure in Swift
... in order to make sure that it is still around by the time the closure is called.
Example: Making an asynchronous network request
If you are making an asynchronous network request you do want the closure to retain self for when the request finishes. That object may have otherwise been deallocated ...
Throw an error in a MySQL trigger
...e SIGNAL syntax to throw an exception:
signal sqlstate '45000' set message_text = 'My Error Message';
State 45000 is a generic state representing "unhandled user-defined exception".
Here is a more complete example of the approach:
delimiter //
use test//
create table trigger_test
(
id int...
Padding is invalid and cannot be removed?
...t are the same. The padding method even if not explicitly set should still allow for proper decryption/encryption (if not set they will be the same). However if you for some reason are using a different set of keys for decryption than used for encryption you will get this error:
Padding is inval...
What is the ellipsis (…) for in this method signature?
...hRecipientJids(jid1, jid2);
msgBuilder2.withRecipientJids(jid1, jid2, jid78_a, someOtherJid);
See more here:
http://java.sun.com/j2se/1.5.0/docs/guide/language/varargs.html
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Oracle query to fetch column names
...tion_schema.COLUMNS is USER_TAB_COLS for tables owned by the current user, ALL_TAB_COLS or DBA_TAB_COLS for tables owned by all users.
Tablespace is not equivalent to a schema, neither do you have to provide the tablespace name.
Providing the schema/username would be of use if you want to query AL...