A simple and useful db wrapper for Crystal-lang
Topaz is a simple and useful db wrapper for crystal lang.
Topaz is inspired by active record design pattern, but not fully implemented.
See sample code for detail.
Here is another sample that shows how Topaz works in Kemal.
Depends on crystal-lang/crystal-mysql, crystal-lang/crystal-sqlite3 and crystal-pg
1. Setup DB
Topaz::Db.setup("mysql://root@localhost/topaz") # For MySQL
Topaz::Db.setup("postgres://root@localhost/topaz") # For PostgreSQL
Topaz::Db.setup("sqlite3://./db/data.db") # For SQLite3
2. Define models
class SampleModel < Topaz::Model
columns(
name: String
)
end
# You can drop or create a table
SampleModel.create_table
SampleModel.drop_table
3. Create, find, update and delete models
s = SampleModel.create("Sample Name")
SampleModel.find(1).name
# => "Sample Name"
SampleModel.where("name = 'Sample Name'").size
# => 1
See sample code for detail.
4. Define associations between models
require "topaz"
class SampleParent < Topaz::Model
columns # Empty columns
has_many(children: {model: SampleChild, key: parent_id})
end
class SampleChild < Topaz::Model
columns( # Define foreign key
parent_id: Int32
)
belongs_to(parent: {model: SampleParent, key: parent_id})
end
p = SampleParent.create
child1 = SampleChild.create(p.id)
child2 = SampleChild.create(p.id)
child3 = SampleChild.create(p.id)
p.children.size
# => 3
child1.parent.id
# => 1
See sample code for detail.
Other features
Model#to_json
and Model#from_json
created_at
and updated_at
columnSee sample codes for detail.
Supported data types.
String, Int32, Int64, Float32, Float64
Setting up PostgreSQL:
$ psql
# CREATE USER root WITH CREATEDB;
# CREATE DATABASE topaz_test WITH OWNER = root;
Setting up MySQL:
$ mysql -u root
mysql> create database topaz_test;