Use model
sub-command to execute generator:
genna model -h
First create your database and tables in it
create table "projects"
(
"projectId" serial not null,
"name" text not null,
primary key ("projectId")
);
create table "users"
(
"userId" serial not null,
"email" varchar(64) not null,
"activated" bool not null default false,
"name" varchar(128),
"countryId" integer,
primary key ("userId")
);
create schema "geo";
create table geo."countries"
(
"countryId" serial not null,
"code" varchar(3) not null,
"coords" integer[],
primary key ("countryId")
);
alter table "users"
add constraint "fk_user_country"
foreign key ("countryId")
references geo."countries" ("countryId") on update restrict on delete restrict;
genna model -c postgres://user:password@localhost:5432/yourdb -o ~/output/model.go -t public.* -f
You should get following models on model package:
//lint:file-ignore U1000 ignore unused code, it's generated
package model
var Columns = struct {
Project struct {
ID, Name string
}
User struct {
ID, Email, Activated, Name, CountryID string
Country string
}
GeoCountry struct {
ID, Code, Coords string
}
}{
Project: struct {
ID, Name string
}{
ID: "projectId",
Name: "name",
},
User: struct {
ID, Email, Activated, Name, CountryID string
Country string
}{
ID: "userId",
Email: "email",
Activated: "activated",
Name: "name",
CountryID: "countryId",
Country: "Country",
},
GeoCountry: struct {
ID, Code, Coords string
}{
ID: "countryId",
Code: "code",
Coords: "coords",
},
}
var Tables = struct {
Project struct {
Name, Alias string
}
User struct {
Name, Alias string
}
GeoCountry struct {
Name, Alias string
}
}{
Project: struct {
Name, Alias string
}{
Name: "projects",
Alias: "t",
},
User: struct {
Name, Alias string
}{
Name: "users",
Alias: "t",
},
GeoCountry: struct {
Name, Alias string
}{
Name: "geo.countries",
Alias: "t",
},
}
type Project struct {
tableName struct{} `sql:"projects,alias:t" pg:",discard_unknown_columns"`
ID int `sql:"projectId,pk"`
Name string `sql:"name,notnull"`
}
type User struct {
tableName struct{} `sql:"users,alias:t" pg:",discard_unknown_columns"`
ID int `sql:"userId,pk"`
Email string `sql:"email,notnull"`
Activated bool `sql:"activated,notnull"`
Name *string `sql:"name"`
CountryID *int `sql:"countryId"`
Country *GeoCountry `pg:"fk:countryId"`
}
type GeoCountry struct {
tableName struct{} `sql:"geo.countries,alias:t" pg:",discard_unknown_columns"`
ID int `sql:"countryId,pk"`
Code string `sql:"code,notnull"`
Coords []int `sql:"coords,array"`
}
package model
import (
"fmt"
"testing"
"github.com/go-pg/pg/v9"
)
const AllColumns = "t.*"
func TestModel(t *testing.T) {
// connecting to db
options, _ := pg.ParseURL("postgres://user:password@localhost:5432/yourdb")
db := pg.Connect(options)
if _, err := db.Exec(`truncate table users; truncate table geo.countries cascade;`); err != nil {
panic(err)
}
// objects to insert
toInsert := []GeoCountry{
GeoCountry{
Code: "us",
Coords: []int{1, 2},
},
GeoCountry{
Code: "uk",
Coords: nil,
},
}
// inserting
if _, err := db.Model(&toInsert).Insert(); err != nil {
panic(err)
}
// selecting
var toSelect []GeoCountry
if err := db.Model(&toSelect).Select(); err != nil {
panic(err)
}
fmt.Printf("%#v\n", toSelect)
// user with fk
newUser := User{
Email: "[email protected]",
Activated: true,
CountryID: &toSelect[0].ID,
}
// inserting
if _, err := db.Model(&newUser).Insert(); err != nil {
panic(err)
}
// selecting inserted user
user := User{}
m := db.Model(&user).
Column(AllColumns, Columns.User.Country).
Where(`? = ?`, pg.F(Columns.User.Email), "[email protected]")
if err := m.Select(); err != nil {
panic(err)
}
fmt.Printf("%#v\n", user)
fmt.Printf("%#v\n", user.Country)
}