granite
kemalyst-model
Kemalyst is a web framework written in the Crystal language.
This project is to provide an ORM Model for Kemalyst.
Installation
Add this library to your projects dependencies along with the driver in
your shard.yml
. This can be used with any framework but was originally
designed to work with kemalyst in mind. This library will work with kemal as
well.
dependencies:
kemalyst-model:
github: drujensen/kemalyst-model
# Pick your database
mysql:
github: crystal-lang/crystal-mysql
sqlite3:
github: crystal-lang/crystal-sqlite3
pg:
github: will/crystal-pg
Next you will need to create a config/database.yml
You can leverage environment variables using ${} syntax.
mysql:
database: "mysql://user:pass@mysql:3306/test"
pg:
database: "postgres://postgres:@pg:5432/postgres"
sqlite:
database: "sqlite3:./config/test.db"
Usage
Here is an example using Kemalyst Model
require "kemalyst-model/adapter/mysql"
class Post < Kemalyst::Model
adapter mysql
field name : String
field body : Text
timestamps
end
Disable the timestamps for SqlLite since TIMESTAMP is not supported for this database:
require "kemalyst-model/adapter/sqlite"
class Comment < Kemalyst::Model
adapter sqlite
table_name post_comments
field name : String
field body : Text
end
Fields
To define the fields for this model, you need to provide a hash with the name of the field and the type.
3 Fields are automatically included for you: id, created_at, updated_at.
Here are the MySQL field definitions for id, created_at, updated_at
id BIGINT NOT NULL AUTO_INCREMENT
# Your fields go here
created_at TIMESTAMP
updated_at TIMESTAMP
PRIMARY KEY (id)
SQL
To clear all the rows in the database:
Post.clear #truncate the table
Find All
posts = Post.all
if posts
posts.each do |post|
puts post.name
end
end
Find
post = Post.find 1
if post
puts post.name
end
Find By
post = Post.find_by :slug, "example_slug"
if post
puts post.name
end
Insert
post = Post.new
post.name = "Kemalyst Rocks!"
post.body = "Check this out."
post.save
Update
post = Post.find 1
post.name = "Kemalyst Really Rocks!"
post.save
Delete
post = Post.find 1
post.destroy
puts "deleted" unless post
Errors
All database errors are added to the errors
array used by Kemalyst::Validators with the symbol ':base'
post = Post.new
post.save
post.errors[0].to_s.should eq "ERROR: name cannot be null"
Queries
The where clause will give you full control over your query.
When using the all
method, the SQL selected fields will always match the
fields specified in the model.
Always pass in parameters to avoid SQL Injection. Use a ?
(or $1
, $2
,.. for pg)
in your query as placeholder. Checkout the Crystal DB Driver
for documentation of the drivers.
Here are some examples:
posts = Post.all("WHERE name LIKE ?", ["Joe%"])
if posts
posts.each do |post|
puts post.name
end
end
# ORDER BY Example
posts = Post.all("ORDER BY created_at DESC")
# JOIN Example
posts = Post.all("JOIN comments c ON c.post_id = post.id
WHERE c.name = ?
ORDER BY post.created_at DESC",
["Joe"])
Contributing
- Fork it ( https://github.com/drujensen/kemalyst-model/fork )
- Create your feature branch (git checkout -b my-new-feature)
- Commit your changes (git commit -am 'Add some feature')
- Push to the branch (git push origin my-new-feature)
- Create a new Pull Request
Contributors
- drujensen drujensen - creator, maintainer