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Jet

Jet is a framework for writing type-safe SQL queries in Go, with ability to easily convert database query result to desired arbitrary object structure.
Jet currently supports PostgreSQL, MySQL and MariaDB. Future releases will add support for additional databases.

Jet is the easiest and fastest way to write complex SQL queries and map database query result into complex object composition. It is not an ORM.

Motivation

https://medium.com/@go.jet/jet-5f3667efa0cc

Installation

Use the bellow command to install jet

$ go get -u github.com/go-jet/jet

Install jet generator to GOPATH bin folder. This will allow generating jet files from the command line.

go install github.com/go-jet/jet/cmd/jet

*Make sure GOPATH bin folder is added to the PATH environment variable.

Usage

Jet requires already defined database schema(with tables, enums etc), so that jet generator can generate SQL Builder and Model files. File generation is very fast, and can be added as every pre-build step. Sample command:

jet -source=PostgreSQL -host=localhost -port=5432 -user=jet -password=pass -dbname=jetdb -schema=dvds -path=some_path

Detail info about jet generator can be found at Generator.

Then next step is to import generated SQL Builder and Model files and write SQL queries in Go:

import . "some_path/.gen/jetdb/dvds/table"
import "some_path/.gen/jetdb/dvds/model"

To write SQL queries for PostgreSQL import:

. "github.com/go-jet/jet/postgres"

To write SQL queries for MySQL and MariaDB import:

. "github.com/go-jet/jet/mysql"

*Dot import so that Go code resemble as much as native SQL. Dot import is not mandatory.

Write SQL:

// sub-query
rRatingFilms := SELECT(
		    Film.FilmID,
		    Film.Title,
		    Film.Rating,
	       ).
               FROM(Film).
	       WHERE(Film.Rating.EQ(enum.FilmRating.R)).
	       AsTable("rFilms")

// export column from sub-query
rFilmID := Film.FilmID.From(rRatingFilms)

// main-query
query := SELECT(
		Actor.AllColumns,
		FilmActor.AllColumns,
		rRatingFilms.AllColumns(),
	).
        FROM(
           rRatingFilms.
	     INNER_JOIN(FilmActor, FilmActor.FilmID.EQ(rFilmID)).
	     INNER_JOIN(Actor, Actor.ActorID.EQ(FilmActor.ActorID)
        ).
	ORDER_BY(rFilmID, Actor.ActorID)

Store result into desired destination:

var dest []struct {
	model.Film

	Actors []model.Actor
}

err := query.Query(db, &dest)