# Simple and performant client for PostgreSQL, MySQL, and SQLite
[](https://github.com/uptrace/bun/actions)
[](https://pkg.go.dev/github.com/uptrace/bun)
[](https://bun.uptrace.dev/)
[](https://discord.gg/rWtp5Aj)
**Status**: API freeze (stable release). Note that all sub-packages (mainly extra/\* packages) are
not part of the API freeze and are developed independently. You can think of them as of 3rd party
packages that share one repo with the core.
Main features are:
- Works with [PostgreSQL](https://bun.uptrace.dev/guide/drivers.html#postgresql),
[MySQL](https://bun.uptrace.dev/guide/drivers.html#mysql) (including MariaDB),
[SQLite](https://bun.uptrace.dev/guide/drivers.html#sqlite).
- [Selecting](/example/basic/) into a map, struct, slice of maps/structs/vars.
- [Bulk inserts](https://bun.uptrace.dev/guide/queries.html#insert).
- [Bulk updates](https://bun.uptrace.dev/guide/queries.html#update) using common table expressions.
- [Bulk deletes](https://bun.uptrace.dev/guide/queries.html#delete).
- [Fixtures](https://bun.uptrace.dev/guide/fixtures.html).
- [Migrations](https://bun.uptrace.dev/guide/migrations.html).
- [Soft deletes](https://bun.uptrace.dev/guide/soft-deletes.html).
Resources:
- [Discussions](https://github.com/uptrace/bun/discussions).
- [Newsletter](https://blog.uptrace.dev/pages/newsletter.html) to get latest updates.
- [Examples](https://github.com/uptrace/bun/tree/master/example)
- [Documentation](https://bun.uptrace.dev/)
- [Reference](https://pkg.go.dev/github.com/uptrace/bun)
- [Starter kit](https://github.com/go-bun/bun-starter-kit)
Projects using Bun:
- [gotosocial](https://github.com/superseriousbusiness/gotosocial) - Golang fediverse server.
- [input-output-hk/cicero](https://github.com/input-output-hk/cicero)
- [RealWorld app](https://github.com/go-bun/bun-realworld-app)
github.com/frederikhors/orm-benchmark results
```
4000 times - Insert
raw_stmt: 0.38s 94280 ns/op 718 B/op 14 allocs/op
raw: 0.39s 96719 ns/op 718 B/op 13 allocs/op
beego_orm: 0.48s 118994 ns/op 2411 B/op 56 allocs/op
bun: 0.57s 142285 ns/op 918 B/op 12 allocs/op
pg: 0.58s 145496 ns/op 1235 B/op 12 allocs/op
gorm: 0.70s 175294 ns/op 6665 B/op 88 allocs/op
xorm: 0.76s 189533 ns/op 3032 B/op 94 allocs/op
4000 times - MultiInsert 100 row
raw: 4.59s 1147385 ns/op 135155 B/op 916 allocs/op
raw_stmt: 4.59s 1148137 ns/op 131076 B/op 916 allocs/op
beego_orm: 5.50s 1375637 ns/op 179962 B/op 2747 allocs/op
bun: 6.18s 1544648 ns/op 4265 B/op 214 allocs/op
pg: 7.01s 1753495 ns/op 5039 B/op 114 allocs/op
gorm: 9.52s 2379219 ns/op 293956 B/op 3729 allocs/op
xorm: 11.66s 2915478 ns/op 286140 B/op 7422 allocs/op
4000 times - Update
raw_stmt: 0.26s 65781 ns/op 773 B/op 14 allocs/op
raw: 0.31s 77209 ns/op 757 B/op 13 allocs/op
beego_orm: 0.43s 107064 ns/op 1802 B/op 47 allocs/op
bun: 0.56s 139839 ns/op 589 B/op 4 allocs/op
pg: 0.60s 149608 ns/op 896 B/op 11 allocs/op
gorm: 0.74s 185970 ns/op 6604 B/op 81 allocs/op
xorm: 0.81s 203240 ns/op 2994 B/op 119 allocs/op
4000 times - Read
raw: 0.33s 81671 ns/op 2081 B/op 49 allocs/op
raw_stmt: 0.34s 85847 ns/op 2112 B/op 50 allocs/op
beego_orm: 0.38s 94777 ns/op 2106 B/op 75 allocs/op
pg: 0.42s 106148 ns/op 1526 B/op 22 allocs/op
bun: 0.43s 106904 ns/op 1319 B/op 18 allocs/op
gorm: 0.65s 162221 ns/op 5240 B/op 108 allocs/op
xorm: 1.13s 281738 ns/op 8326 B/op 237 allocs/op
4000 times - MultiRead limit 100
raw: 1.52s 380351 ns/op 38356 B/op 1037 allocs/op
raw_stmt: 1.54s 385541 ns/op 38388 B/op 1038 allocs/op
pg: 1.86s 465468 ns/op 24045 B/op 631 allocs/op
bun: 2.58s 645354 ns/op 30009 B/op 1122 allocs/op
beego_orm: 2.93s 732028 ns/op 55280 B/op 3077 allocs/op
gorm: 4.97s 1241831 ns/op 71628 B/op 3877 allocs/op
xorm: doesn't work
```
## Why another database client?
So you can elegantly write complex queries:
```go
regionalSales := db.NewSelect().
ColumnExpr("region").
ColumnExpr("SUM(amount) AS total_sales").
TableExpr("orders").
GroupExpr("region")
topRegions := db.NewSelect().
ColumnExpr("region").
TableExpr("regional_sales").
Where("total_sales > (SELECT SUM(total_sales) / 10 FROM regional_sales)")
err := db.NewSelect().
With("regional_sales", regionalSales).
With("top_regions", topRegions).
ColumnExpr("region").
ColumnExpr("product").
ColumnExpr("SUM(quantity) AS product_units").
ColumnExpr("SUM(amount) AS product_sales").
TableExpr("orders").
Where("region IN (SELECT region FROM top_regions)").
GroupExpr("region").
GroupExpr("product").
Scan(ctx)
```
```sql
WITH regional_sales AS (
SELECT region, SUM(amount) AS total_sales
FROM orders
GROUP BY region
), top_regions AS (
SELECT region
FROM regional_sales
WHERE total_sales > (SELECT SUM(total_sales)/10 FROM regional_sales)
)
SELECT region,
product,
SUM(quantity) AS product_units,
SUM(amount) AS product_sales
FROM orders
WHERE region IN (SELECT region FROM top_regions)
GROUP BY region, product
```
## Installation
```go
go get github.com/uptrace/bun
```
You also need to install a database/sql driver and the corresponding Bun
[dialect](https://bun.uptrace.dev/guide/drivers.html).
## Quickstart
First you need to create a `sql.DB`. Here we are using the
[sqliteshim](https://pkg.go.dev/github.com/uptrace/bun/driver/sqliteshim) driver which chooses
between [modernc.org/sqlite](https://modernc.org/sqlite/) and
[mattn/go-sqlite3](https://github.com/mattn/go-sqlite3) depending on your platform.
```go
import "github.com/uptrace/bun/driver/sqliteshim"
sqldb, err := sql.Open(sqliteshim.ShimName, "file::memory:?cache=shared")
if err != nil {
panic(err)
}
```
And then create a `bun.DB` on top of it using the corresponding SQLite
[dialect](https://bun.uptrace.dev/guide/drivers.html) that comes with Bun:
```go
import (
"github.com/uptrace/bun"
"github.com/uptrace/bun/dialect/sqlitedialect"
)
db := bun.NewDB(sqldb, sqlitedialect.New())
```
Now you are ready to issue some queries:
```go
type User struct {
ID int64
Name string
}
user := new(User)
err := db.NewSelect().
Model(user).
Where("name != ?", "").
OrderExpr("id ASC").
Limit(1).
Scan(ctx)
```
## Basic example
To provide initial data for our [example](/example/basic/), we will use Bun
[fixtures](https://bun.uptrace.dev/guide/fixtures.html):
```go
import "github.com/uptrace/bun/dbfixture"
// Register models for the fixture.
db.RegisterModel((*User)(nil), (*Story)(nil))
// WithRecreateTables tells Bun to drop existing tables and create new ones.
fixture := dbfixture.New(db, dbfixture.WithRecreateTables())
// Load fixture.yaml which contains data for User and Story models.
if err := fixture.Load(ctx, os.DirFS("."), "fixture.yaml"); err != nil {
panic(err)
}
```
The `fixture.yaml` looks like this:
```yaml
- model: User
rows:
- _id: admin
name: admin
emails: ['admin1@admin', 'admin2@admin']
- _id: root
name: root
emails: ['root1@root', 'root2@root']
- model: Story
rows:
- title: Cool story
author_id: '{{ $.User.admin.ID }}'
```
To select all users:
```go
users := make([]User, 0)
if err := db.NewSelect().Model(&users).OrderExpr("id ASC").Scan(ctx); err != nil {
panic(err)
}
```
To select a single user by id:
```go
user1 := new(User)
if err := db.NewSelect().Model(user1).Where("id = ?", 1).Scan(ctx); err != nil {
panic(err)
}
```
To select a story and the associated author in a single query:
```go
story := new(Story)
if err := db.NewSelect().
Model(story).
Relation("Author").
Limit(1).
Scan(ctx); err != nil {
panic(err)
}
```
To select a user into a map:
```go
m := make(map[string]interface{})
if err := db.NewSelect().
Model((*User)(nil)).
Limit(1).
Scan(ctx, &m); err != nil {
panic(err)
}
```
To select all users scanning each column into a separate slice:
```go
var ids []int64
var names []string
if err := db.NewSelect().
ColumnExpr("id, name").
Model((*User)(nil)).
OrderExpr("id ASC").
Scan(ctx, &ids, &names); err != nil {
panic(err)
}
```
For more details, please consult [docs](https://bun.uptrace.dev/) and check [examples](example).
## Contributors
Thanks to all the people who already contributed!
