Has one relation¶
In the the following example we have a User
model that has one Profile
model.
type Profile struct {
Id int
Lang string
}
// User has one profile.
type User struct {
Id int
Name string
ProfileId int
Profile *Profile `pg:"rel:has-one"`
}
db := connect()
defer db.Close()
qs := []string{
"CREATE TEMP TABLE users (id int, name text, profile_id int)",
"CREATE TEMP TABLE profiles (id int, lang text)",
"INSERT INTO users VALUES (1, 'user 1', 1), (2, 'user 2', 2)",
"INSERT INTO profiles VALUES (1, 'en'), (2, 'ru')",
}
for _, q := range qs {
_, err := db.Exec(q)
if err != nil {
panic(err)
}
}
// Select users joining their profiles with following query:
//
// SELECT
// "user".*,
// "profile"."id" AS "profile__id",
// "profile"."lang" AS "profile__lang",
// "profile"."user_id" AS "profile__user_id"
// FROM "users" AS "user"
// LEFT JOIN "profiles" AS "profile" ON "profile"."user_id" = "user"."id"
var users []User
err := db.Model(&users).
Column("user.*").
Relation("Profile").
Select()
if err != nil {
panic(err)
}
fmt.Println(len(users), "results")
fmt.Println(users[0].Id, users[0].Name, users[0].Profile)
fmt.Println(users[1].Id, users[1].Name, users[1].Profile)
// Output: 2 results
// 1 user 1 &{1 en}
// 2 user 2 &{2 ru}