SebastianSzturo / jennifer_sqlite3_adapter

SQLite3 adapter for Jennifer ORM

Jennifer SQLite3 adapter

SQLite3 adapter for Jennifer.

Installation

1. Add the dependencies to your shard.yml:

dependencies:
  sqlite3:
    github: crystal-lang/crystal-sqlite3
    version: "0.18.0"
  jennifer_sqlite3_adapter:
    github: imdrasil/jennifer_sqlite3_adapter
    version: "~> 0.4.0"

Current adapter version is tested with 0.18.0 sqlite3 driver but other versions may also work

2. Run shards install

Usage

This shard supports Jennifer 0.12.0 and above. It is tested with SQLite 3.31.1 version. Some of features may not work on older versions.

require "jennifer"
require "jennifer_sqlite3_adapter"

Jennifer::Config.configure do |conf|
  conf.adapter = "sqlite3"
  conf.host = "."
  conf.db = "test.db"
end

user and password configurations are not required as SQLite doesn't provide user authentication and they are ignored. host options is used to specify database file folder path, db - file name.

Supported data types

Method	SQLite3	Crystal type
#bool	INTEGER	Bool
#integer	INTEGER	Int32
#bigint	INTEGER	Int32
#short	INTEGER	Int32
#tinyint	INTEGER	Int32
#float	REAL	Float64
#double	REAL	Float64
#real	REAL	Float64
#text	TEXT	String
#string	TEXT	String
#varchar	TEXT	String
#date_time	TEXT	Time
#timestamp	TEXT	Time

Altering table

SQLite has no mechanism to alter existing table (except renaming it). Therefore operations, listed below, do multiple steps to achieve altering table: coping table schema to new temp table, coping data to new table, extending new table with required options, dropping old table and renaming temp table to original name:

• dropping column
• changing column
• adding foreign key
• dropping foreign key

It is necessary to notice that all those operations keep all data and indexes.

Foreign key

At a startup adapter automatically enable foreign keys executing PRAGMA foreign_keys = ON. But be aware using migrations - as described above, some table manipulations will recreate a table. To avoid breaking of any foreign key, adapter will try to disable them until the end of a manipulation, but this is possible only outside of a transaction. Therefore in a such kind of migrations add with_transaction false at the class body to disable automatic transaction around migration methods.

Contributing

1. Fork it (https://github.com/imdrasil/jennifer_sqlite3_adapter/fork)
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request

Contributors

• Roman Kalnytskyi - creator and maintainer