Tutorial by Examples: ase

To use multiple databases in Django, just specify each one in settings.py: DATABASES = { 'default': { 'NAME': 'app_data', 'ENGINE': 'django.db.backends.postgresql', 'USER': 'django_db_user', 'PASSWORD': os.environ['LOCAL_DB_PASSWORD'] }, 'users': {...

The normal obj.save() method will use the default database, or if a database router is used, it will use the database as specified in db_for_write. You can override it by using: obj.save(using='other_db') obj.delete(using='other_db') Similarly, for reading: MyModel.objects.using('other_db').al...

With the Class Based generic Views, it is very simple and easy to create the CRUD views from our models. Often, the built in Django admin is not enough or not preferred and we need to roll our own CRUD views. The CBVs can be very handy in such cases. The CreateView class needs 3 things - a model, t...

(u)gettext_noop allows you to mark a string as translatable without actually translating it. A typical use case is when you want to log a message for developers (in English) but also want to display it to the client (in the requested language). You can pass a variable to gettext, but its content wo...

Example uses basic HTTP syntax. Any <#> in the example should be removed when copying it. The _cat APIs are often convenient for humans to get at-a-glance details about the cluster. But you frequently want consistently parseable output to use with software. In general, the JSON APIs are meant...

The following example encrypts a given data block using AES. The encryption key is derived in a secure way (random salt, 1000 rounds of SHA-256). The encryption uses AES in CBC mode with random IV. Note that the data stored in the class EncryptedData (salt, iv, and encryptedData) can be concatenate...

add filter method in RecyclerView.Adapter: public void filter(String text) { if(text.isEmpty()){ items.clear(); items.addAll(itemsCopy); } else{ ArrayList<PhoneBookItem> result = new ArrayList<>(); text = text.toLower...

Create Oracle error log table ERR$_EXAMPLE for existing EXAMPLE table: EXECUTE DBMS_ERRLOG.CREATE_ERROR_LOG('EXAMPLE', NULL, NULL, NULL, TRUE); Make writing operation with SQL: insert into EXAMPLE (COL1) values ('example') LOG ERRORS INTO ERR$_EXAMPLE reject limit unlimited;

Simple case without duplicate keys Stream<String> characters = Stream.of("A", "B", "C"); Map<Integer, String> map = characters .collect(Collectors.toMap(element -> element.hashCode(), element -> element)); // map = {65=A, 66=B, 67=C} ...

You will have to inject $filter: angular .module('filters', []) .filter('percentage', function($filter) { return function (input) { return $filter('number')(input * 100) + ' %'; }; });

The System.String class supports a number of methods to convert between uppercase and lowercase characters in a string. System.String.ToLowerInvariant is used to return a String object converted to lowercase. System.String.ToUpperInvariant is used to return a String object converted to upper...

Sometimes we need preserve whole model and transfer it across actions or even controllers. Storing model at session good solution for this type of requirements. If we combine this with powerful model binding features of MVC we get elegant way of doing so. We can create generic session based model bi...

HTTP requests are widely used repeatedly across every web app, so it is wise to write a method for each common request, and then use it in multiple places throughout the app. Create a httpRequestsService.js httpRequestsService.js appName.service('httpRequestsService', function($q, $http){ ...

You will need to set your base URL in application/config/config.php If it is not set, then CodeIgniter will try to guess the protocol and path to your installation, but due to the security concerns the hostname will be set to $_SERVER['SERVER_ADDR'] if available, or localhost otherwise. The auto...

Longer portions of text containing special characters can be escaped with a CDATA section. CDATA sections can only appear in element content. <?xml version="1.0"?> <document> This is a CDATA section : <![CDATA[ plenty of special characters like & < > " ; ...

You'll need to separate out your application layer from your database layer, and that means specifying the MONGO_URL. Which means running your app through the bundle command, uncompressing it, setting environment variables, and then launching the project as a node app. Here's how... #make sure you...

Then go into the mongo shell and initiate the replica set, like so: mongo > rs.initiate() PRIMARY> rs.add("mongo-a") PRIMARY> rs.add("mongo-b") PRIMARY> rs.add("mongo-c") PRIMARY> rs.setReadPref('secondaryPreferred')

The replica set will need an oplog user to access the database. mongo PRIMARY> use admin PRIMARY> db.addUser({user:"oplogger",pwd:"YOUR_PASSWORD",roles:[],otherDBRoles:{local:["read"]}}); PRIMARY> show users

There's two great utilities for black-box analysis of databases. First is variety.js, which will give you a high-level overview. The second is schema.js, which will let you dig into the collections for more detail on the individual fields. When inheriting a production Mongo database, these two util...

The --url flag can be tricky to use. There is a 60 second window to authenticate, and then the username/password randomly resets. So be sure to have robomongo open and ready to configure a new connection when you run the command. # get the MONGO_URL string for your app meteor mongo --url $METEOR...