Tutorial by Topics: es

from django.contrib.postgres.fields import ArrayField class ArrayField(base_field, size=None, **options) FooModel.objects.filter(array_field_name__contains=[objects, to, check]) FooModel.objects.filter(array_field_name__contained_by=[objects, to, check]) Note that although the size param...

There are some cases where your application cannot manipulate the contents of assets loaded from an external resource (e.g. transform images). I can't remember for certain what they are, but I am fairly sure it's related to cross domain content loading.

Stored Procedures are SQL statements stored in the database that can be executed or called in queries. Using a stored procedure allows encapsulation of complicated or frequently used logic, and improves query performance by utilizing cached query plans. They can return any value a standard query c...

install.packages(pkgs, lib, repos, method, destdir, dependencies, ...) ParameterDetailspkgscharacter vector of the names of packages. If repos = NULL, a character vector of file paths.libcharacter vector giving the library directories where to install the packages.reposcharacter vector, the...

-- Create simple index CREATE INDEX index_name ON table_name(column_name1 [, column_name2, ...]) -- Create unique index CREATE UNIQUE INDEX index_name ON table_name(column_name1 [, column_name2, ...] -- Drop index DROP INDEX index_name ON tbl_name [algorithm_option | lock_option] ....

CSS Variables allow authors to create reusable values which can be used throughout a CSS document. For example, it's common in CSS to reuse a single color throughout a document. Prior to CSS Variables this would mean reusing the same color value many times throughout a document. With CSS Variables ...

Simple classes RegexMatches[abc]Any of the following characters: a, b, or c[a-z]Any character from a to z, inclusive (this is called a range)[0-9]Any digit from 0 to 9, inclusive Common classes Some groups/ranges of characters are so often used, they have special abbreviations: RegexMatche...

JSONField(**options) Django's JSONField actually stores the data in a Postgres JSONB column, which is only available in Postgres 9.4 and later. JSONField is great when you want a more flexible schema. For example if you want to change the keys without having to do any data migratio...

window.requestAnimationFrame(callback); window.webkitRequestAnimationFrame(callback); window.mozRequestAnimationFrame(callback); ParameterDetailscallback"A parameter specifying a function to call when it's time to update your animation for the next repaint." (https://developer.mo...

@property (optional_attributes, ...) type identifier; @synthesize identifier = optional_backing_ivar; @dynamic identifier; AttributeDescriptionatomicImplicit. Enables synchronization in synthesized accessor methods.nonatomicDisables synchronization in the synthesized accessor methods.read...