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GitHub - go-pg/pg: Golang ORM with focus on PostgreSQL features and performance
source link: https://github.com/go-pg/pg
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README.md
PostgreSQL client and ORM for Golang
Features:
- Basic types: integers, floats, string, bool, time.Time, net.IP, net.IPNet.
- sql.NullBool, sql.NullString, sql.NullInt64, sql.NullFloat64 and pg.NullTime.
- sql.Scanner and sql/driver.Valuer interfaces.
- Structs, maps and arrays are marshalled as JSON by default.
- PostgreSQL multidimensional Arrays using array tag and Array wrapper.
- Hstore using hstore tag and Hstore wrapper.
- Composite types.
- All struct fields are nullable by default and zero values (empty string, 0, zero time, empty map or slice, nil ptr) are marshalled as SQL
NULL
.sql:",notnull"
is used to add SQLNOT NULL
constraint andpg:",use_zero"
to allow Go zero values. - Transactions.
- Prepared statements.
- Notifications using
LISTEN
andNOTIFY
. - Copying data using
COPY FROM
andCOPY TO
. - Timeouts and canceling queries using context.Context.
- Automatic connection pooling with circuit breaker support.
- Queries retries on network errors.
- Working with models using ORM and SQL.
- Scanning variables using ORM and SQL.
- SelectOrInsert using on-conflict.
- INSERT ... ON CONFLICT DO UPDATE using ORM.
- Bulk/batch inserts, updates, and deletes.
- Common table expressions using WITH and WrapWith.
- CountEstimate using
EXPLAIN
to get estimated number of matching rows. - ORM supports has one, belongs to, has many, and many to many with composite/multi-column primary keys.
- Soft deletes.
- Creating tables from structs.
- Pagination and URL filters helpers.
- ForEach that calls a function for each row returned by the query without loading all rows into the memory.
- Works with PgBouncer in transaction pooling mode.
- Migrations.
- Sharding.
- Model generator from SQL tables.
Get Started
go-pg requires Go version with Modules support and uses import versioning:
go get github.com/go-pg/pg/v9
Look & Feel
package pg_test import ( "fmt" "github.com/go-pg/pg/v9" "github.com/go-pg/pg/v9/orm" ) type User struct { Id int64 Name string Emails []string } func (u User) String() string { return fmt.Sprintf("User<%d %s %v>", u.Id, u.Name, u.Emails) } type Story struct { Id int64 Title string AuthorId int64 Author *User } func (s Story) String() string { return fmt.Sprintf("Story<%d %s %s>", s.Id, s.Title, s.Author) } func ExampleDB_Model() { db := pg.Connect(&pg.Options{ User: "postgres", }) defer db.Close() err := createSchema(db) if err != nil { panic(err) } user1 := &User{ Name: "admin", Emails: []string{"admin1@admin", "admin2@admin"}, } err = db.Insert(user1) if err != nil { panic(err) } err = db.Insert(&User{ Name: "root", Emails: []string{"root1@root", "root2@root"}, }) if err != nil { panic(err) } story1 := &Story{ Title: "Cool story", AuthorId: user1.Id, } err = db.Insert(story1) if err != nil { panic(err) } // Select user by primary key. user := &User{Id: user1.Id} err = db.Select(user) if err != nil { panic(err) } // Select all users. var users []User err = db.Model(&users).Select() if err != nil { panic(err) } // Select story and associated author in one query. story := new(Story) err = db.Model(story). Relation("Author"). Where("story.id = ?", story1.Id). Select() if err != nil { panic(err) } fmt.Println(user) fmt.Println(users) fmt.Println(story) // Output: User<1 admin [admin1@admin admin2@admin]> // [User<1 admin [admin1@admin admin2@admin]> User<2 root [root1@root root2@root]>] // Story<1 Cool story User<1 admin [admin1@admin admin2@admin]>> } func createSchema(db *pg.DB) error { for _, model := range []interface{}{(*User)(nil), (*Story)(nil)} { err := db.CreateTable(model, &orm.CreateTableOptions{ Temp: true, }) if err != nil { return err } } return nil }
See also
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