# upper.io/db.v3 [](https://travis-ci.org/upper/db) [](https://godoc.org/upper.io/db.v3)
The `upper.io/db.v3` package for [Go][2] is a productive data access layer for
Go that provides a common interface to work with different data sources such as
[PostgreSQL](https://upper.io/db.v3/postgresql),
[MySQL](https://upper.io/db.v3/mysql), [SQLite](https://upper.io/db.v3/sqlite),
[MSSQL](https://upper.io/db.v3/mssql),
[QL](https://upper.io/db.v3/ql) and [MongoDB](https://upper.io/db.v3/mongodb).
```
go get upper.io/db.v3
```
## The tour
Take the [tour](https://tour.upper.io) to see real live examples in your
browser.
## Live demos
You can run the following example on our [playground](https://demo.upper.io):
```go
package main
import (
"log"
"upper.io/db.v3/postgresql"
)
var settings = postgresql.ConnectionURL{
Host: "demo.upper.io",
Database: "booktown",
User: "demouser",
Password: "demop4ss",
}
type Book struct {
ID int `db:"id"`
Title string `db:"title"`
AuthorID int `db:"author_id"`
SubjectID int `db:"subject_id"`
}
func main() {
sess, err := postgresql.Open(settings)
if err != nil {
log.Fatalf("db.Open(): %q\n", err)
}
defer sess.Close()
var books []Book
err = sess.Collection("books").Find().All(&books)
if err != nil {
log.Fatalf("Find(): %q\n", err)
}
for i, book := range books {
log.Printf("Book %d: %#v\n", i, book)
}
}
```
Or you can also run it locally from the `_examples` directory:
```
go run _examples/booktown-books/main.go
2016/08/10 08:42:48 "The Shining" (ID: 7808)
2016/08/10 08:42:48 "Dune" (ID: 4513)
2016/08/10 08:42:48 "2001: A Space Odyssey" (ID: 4267)
2016/08/10 08:42:48 "The Cat in the Hat" (ID: 1608)
2016/08/10 08:42:48 "Bartholomew and the Oobleck" (ID: 1590)
2016/08/10 08:42:48 "Franklin in the Dark" (ID: 25908)
2016/08/10 08:42:48 "Goodnight Moon" (ID: 1501)
2016/08/10 08:42:48 "Little Women" (ID: 190)
2016/08/10 08:42:48 "The Velveteen Rabbit" (ID: 1234)
2016/08/10 08:42:48 "Dynamic Anatomy" (ID: 2038)
2016/08/10 08:42:48 "The Tell-Tale Heart" (ID: 156)
2016/08/10 08:42:48 "Programming Python" (ID: 41473)
2016/08/10 08:42:48 "Learning Python" (ID: 41477)
2016/08/10 08:42:48 "Perl Cookbook" (ID: 41478)
2016/08/10 08:42:48 "Practical PostgreSQL" (ID: 41472)
```
## Documentation for users
This is the source code repository, check out our [release
notes](https://github.com/upper/db/releases/tag/v3.0.0) and see examples and
documentation at [upper.io/db.v3][1].
## Changelog
See [CHANGELOG.md](https://github.com/upper/db/blob/master/CHANGELOG.md).
## License
This project is licensed under the terms of the **MIT License**.
> Copyright (c) 2012-present The upper.io/db authors. All rights reserved.
>
> Permission is hereby granted, free of charge, to any person obtaining
> a copy of this software and associated documentation files (the
> "Software"), to deal in the Software without restriction, including
> without limitation the rights to use, copy, modify, merge, publish,
> distribute, sublicense, and/or sell copies of the Software, and to
> permit persons to whom the Software is furnished to do so, subject to
> the following conditions:
>
> The above copyright notice and this permission notice shall be
> included in all copies or substantial portions of the Software.
>
> THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
> EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
> MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
> NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
> LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
> OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
> WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
## Authors and contributors
* José Carlos Nieto <>
* Peter Kieltyka <>
* Maciej Lisiewski <>
* Max Hawkins <>
* Paul Xue <>
* Kevin Darlington <>
* Lars Buitinck <>
* icattlecoder <>
* Aaron <>
* Hiram J. Pérez <>
* Julien Schmidt <>
* Max Hawkins <>
* Piotr "Orange" Zduniak <>
* achun <>
* rjmcguire <>
* wei2912 <>
[1]: https://upper.io/db.v3
[2]: http://golang.org