🚀 GocqlX

GocqlX makes working with Scylla easy and less error-prone. It’s inspired by Sqlx, a tool for working with SQL databases, but it goes beyond what Sqlx provides.

Features

• Binding query parameters from struct fields, map, or both
• Scanning query results into structs based on field names
• Convenient functions for common tasks such as loading a single row into a struct or all rows into a slice (list) of structs
• Making any struct a UDT without implementing marshalling functions
• GocqlX is fast. Its performance is comparable to raw driver. You can find some benchmarks here.

Subpackages provide additional functionality:

• CQL query builder (package qb)
• CRUD operations based on table model (package table)
• Database migrations (package migrate)

Installation

git clone git@github.com:scylladb/gocqlx.git
cd gocqlx/cmd/schemagen/
go install .

Getting started

Wrap gocql Session:

// Create gocql cluster.
cluster := gocql.NewCluster(hosts...)
// Wrap session on creation, gocqlx session embeds gocql.Session pointer. 
session, err := gocqlx.WrapSession(cluster.CreateSession())
if err != nil {
	t.Fatal(err)
}

Specify table model:

// metadata specifies table name and columns it must be in sync with schema.
var personMetadata = table.Metadata{
	Name:    "person",
	Columns: []string{"first_name", "last_name", "email"},
	PartKey: []string{"first_name"},
	SortKey: []string{"last_name"},
}

// personTable allows for simple CRUD operations based on personMetadata.
var personTable = table.New(personMetadata)

// Person represents a row in person table.
// Field names are converted to snake case by default, no need to add special tags.
// A field will not be persisted by adding the `db:"-"` tag or making it unexported.
type Person struct {
	FirstName string
	LastName  string
	Email     []string
	HairColor string `db:"-"`  // exported and skipped
	eyeColor  string           // unexported also skipped
}

Bind data from a struct and insert a row:

p := Person{
	"Michał",
	"Matczuk",
	[]string{"michal@scylladb.com"},
	"red",    // not persisted
	"hazel"   // not persisted
}
q := session.Query(personTable.Insert()).BindStruct(p)
if err := q.ExecRelease(); err != nil {
	t.Fatal(err)
}

Load a single row to a struct:

p := Person{
	"Michał",
	"Matczuk",
	nil, // no email
}
q := session.Query(personTable.Get()).BindStruct(p)
if err := q.GetRelease(&p); err != nil {
	t.Fatal(err)
}
t.Log(p)
// stdout: {Michał Matczuk [michal@scylladb.com]}

Load all rows in to a slice:

var people []Person
q := session.Query(personTable.Select()).BindMap(qb.M{"first_name": "Michał"})
if err := q.SelectRelease(&people); err != nil {
	t.Fatal(err)
}
t.Log(people)
// stdout: [{Michał Matczuk [michal@scylladb.com]}]

Generating table metadata with schemagen

Installation

go get -u "github.com/scylladb/gocqlx/v3/cmd/schemagen"

Usage:

schemagen [flags]

Flags:
  -cluster string
    	a comma-separated list of host:port tuples (default "127.0.0.1")
  -keyspace string
    	keyspace to inspect (required)
  -output string
    	the name of the folder to output to (default "models")
  -pkgname string
    	the name you wish to assign to your generated package (default "models") 

Example:

Running the following command for examples keyspace:

schemagen -cluster="127.0.0.1:9042" -keyspace="examples" -output="models" -pkgname="models"

Generates models/models.go as follows:

// Code generated by "gocqlx/cmd/schemagen"; DO NOT EDIT.

package models

import "github.com/scylladb/gocqlx/v3/table"

// Table models.
var (
	Playlists = table.New(table.Metadata{
		Name: "playlists",
		Columns: []string{
			"album",
			"artist",
			"id",
			"song_id",
			"title",
		},
		PartKey: []string{
			"id",
		},
		SortKey: []string{
			"title",
			"album",
			"artist",
		},
	})

	Songs = table.New(table.Metadata{
		Name: "songs",
		Columns: []string{
			"album",
			"artist",
			"data",
			"id",
			"tags",
			"title",
		},
		PartKey: []string{
			"id",
		},
		SortKey: []string{},
	})
)

Examples

You can find lots of examples in example_test.go.

Go and run them locally:

make run-scylla
make run-examples

Training

The course Using Scylla Drivers in Scylla University explains how to use drivers in different languages to interact with a Scylla cluster. The lesson, Golang and Scylla Part 3 - GoCQLX, goes over a sample application that, using GoCQLX, interacts with a three-node Scylla cluster. It connects to a Scylla cluster, displays the contents of a table, inserts and deletes data, and shows the contents of the table after each action. Scylla University includes other training material and online courses which will help you become a Scylla NoSQL database expert.

Performance

GocqlX performance is comparable to the raw gocql driver. Below benchmark results running on my laptop.

BenchmarkBaseGocqlInsert            2392            427491 ns/op            7804 B/op         39 allocs/op
BenchmarkGocqlxInsert               2479            435995 ns/op            7803 B/op         39 allocs/op
BenchmarkBaseGocqlGet               2853            452384 ns/op            7309 B/op         35 allocs/op
BenchmarkGocqlxGet                  2706            442645 ns/op            7646 B/op         38 allocs/op
BenchmarkBaseGocqlSelect             747           1664365 ns/op           49415 B/op        927 allocs/op
BenchmarkGocqlxSelect                667           1877859 ns/op           42521 B/op        932 allocs/op

See the benchmark in benchmark_test.go.

License

Copyright (C) 2017 ScyllaDB

This project is distributed under the Apache 2.0 license. See the LICENSE file for details. It contains software from:

• gocql project, licensed under the BSD license
• sqlx project, licensed under the MIT license

Apache®, Apache Cassandra® are either registered trademarks or trademarks of the Apache Software Foundation in the United States and/or other countries. No endorsement by The Apache Software Foundation is implied by the use of these marks.

GitHub star is always appreciated!