A better ORM for Go and database/sql
.
It uses non-empty interfaces, code generation (go generate
), and initialization-time reflection
as opposed to interface{}
, type system sidestepping, and runtime reflection. It will be kept simple.
Supported SQL dialects:
RDBMS | Library and drivers | Status |
---|---|---|
PostgreSQL | github.com/lib/pq (postgres ) |
Stable. Tested with all supported versions. |
github.com/jackc/pgx/stdlib (pgx v3) |
Stable. Tested with all supported versions. | |
MySQL | github.com/go-sql-driver/mysql (mysql ) |
Stable. Tested with all supported versions. |
SQLite3 | github.com/mattn/go-sqlite3 (sqlite3 ) |
Stable. |
Microsoft SQL Server | github.com/denisenkom/go-mssqldb (sqlserver , mssql ) |
Stable. Tested on Windows with: SQL2008R2SP2, SQL2012SP1, SQL2014, SQL2016. On Linux with: mcr.microsoft.com/mssql/server:2017-latest and mcr.microsoft.com/mssql/server:2019-latest Docker images. |
Notes:
clientFoundRows=true
flag is required formysql
driver.mssql
driver is deprecated (but notsqlserver
driver).
-
Make sure you are using Go 1.17+, and Go modules support is enabled. Install or update
reform
package,reform
andreform-db
commands with:go get -v gopkg.in/reform.v1/...
If you are not using Go modules yet, you can use dep to vendor desired version of reform, and then install commands with:
go install -v ./vendor/gopkg.in/reform.v1/...
You can also install the latest stable version of reform without using Go modules thanks to gopkg.in redirection, but please note that this will not use the stable versions of the database drivers:
env GO111MODULE=off go get -u -v gopkg.in/reform.v1/...
Canonical import path is
gopkg.in/reform.v1
; usinggithub.com/go-reform/reform
will not work.See note about versioning and branches below.
-
Use
reform-db
command to generate models for your existing database schema. For example:reform-db -db-driver=sqlite3 -db-source=example.sqlite3 init
-
Update generated models or write your own –
struct
representing a table or view row. For example, store this in fileperson.go
://go:generate reform //reform:people type Person struct { ID int32 `reform:"id,pk"` Name string `reform:"name"` Email *string `reform:"email"` CreatedAt time.Time `reform:"created_at"` UpdatedAt *time.Time `reform:"updated_at"` }
Magic comment
//reform:people
links this model topeople
table or view in SQL database. The first value in field'sreform
tag is a column name.pk
marks primary key. Use value-
or omit tag completely to skip a field. Use pointers (recommended) orsql.NullXXX
types for nullable fields. -
Run
reform [package or directory]
orgo generate [package or file]
. This will createperson_reform.go
in the same package with typePersonTable
and methods onPerson
. -
See documentation how to use it. Simple example:
// Get *sql.DB as usual. PostgreSQL example: sqlDB, err := sql.Open("postgres", "postgres:https://127.0.0.1:5432/database") if err != nil { log.Fatal(err) } defer sqlDB.Close() // Use new *log.Logger for logging. logger := log.New(os.Stderr, "SQL: ", log.Flags()) // Create *reform.DB instance with simple logger. // Any Printf-like function (fmt.Printf, log.Printf, testing.T.Logf, etc) can be used with NewPrintfLogger. // Change dialect for other databases. db := reform.NewDB(sqlDB, postgresql.Dialect, reform.NewPrintfLogger(logger.Printf)) // Save record (performs INSERT or UPDATE). person := &Person{ Name: "Alexey Palazhchenko", Email: pointer.ToString("[email protected]"), } if err := db.Save(person); err != nil { log.Fatal(err) } // ID is filled by Save. person2, err := db.FindByPrimaryKeyFrom(PersonTable, person.ID) if err != nil { log.Fatal(err) } fmt.Println(person2.(*Person).Name) // Delete record. if err = db.Delete(person); err != nil { log.Fatal(err) } // Find records by IDs. persons, err := db.FindAllFrom(PersonTable, "id", 1, 2) if err != nil { log.Fatal(err) } for _, p := range persons { fmt.Println(p) }
reform was born during summer 2014 out of frustrations with existing Go ORMs. All of them have a method
Save(record interface{})
which can be used like this:
orm.Save(User{Name: "gopher"})
orm.Save(&User{Name: "gopher"})
orm.Save(nil)
orm.Save("Batman!!")
Now you can say that last invocation is obviously invalid, and that it's not hard to make an ORM to accept both first and second versions. But there are two problems:
- Compiler can't check it. Method's signature in
godoc
will not tell us how to use it. We are essentially working against those tools by sidestepping type system. - First version is still invalid, since one would expect
Save()
method to set record's primary key afterINSERT
, but this change will be lost due to passing by value.
First proprietary version of reform was used in production even before go generate
announcement.
This free and open-source version is the fourth milestone on the road to better and idiomatic API.
We are following Semantic Versioning, using gopkg.in and filling a changelog. All v1 releases are SemVer-compatible; breaking changes will not be applied.
We use tags v1.M.m
for releases, branch main
(default on GitHub) for the next minor release development,
and release/1.M
branches for patch release development. (It was more complicated before 1.4.0 release.)
Major version 2 is currently not planned.
- github.com/AlekSi/pointer is very useful for working with reform structs with pointers.
- There should be zero
pk
fields for Struct and exactly onepk
field for Record. Composite primary keys are not supported (#114). pk
field can't be a pointer (== nil
doesn't work).- Database row can't have a Go's zero value (0, empty string, etc.) in primary key column.
Code is covered by standard MIT-style license. Copyright (c) 2016-2020 Alexey Palazhchenko. See LICENSE for details. Note that generated code is covered by the terms of your choice.
The reform gopher was drawn by Natalya Glebova. Please use it only as reform logo. It is based on the original design by Renée French, released under Creative Commons Attribution 3.0 USA license.