examples/ogx/example/rel-belongs-to/main.go

99 lines
2.2 KiB
Go

package main
import (
"context"
"database/sql"
"fmt"
"gitee.com/chentanyang/ogx"
"gitee.com/chentanyang/ogx/dialect/ogdialect"
"gitee.com/chentanyang/ogx/extra/ogxdebug"
_ "gitee.com/opengauss/openGauss-connector-go-pq"
)
type Profile struct {
ID int64 `ogx:",pk,autoincrement"`
Lang string
}
// User has one profile.
type User struct {
ID int64 `ogx:",pk,autoincrement"`
Name string
ProfileID int64
Profile *Profile `ogx:"rel:belongs-to,join=profile_id=id"`
}
func main() {
ctx := context.Background()
connStr := "host=192.168.20.40 port=26000 user=cuih password=Gauss@123 dbname=test sslmode=disable"
opengaussdb, err := sql.Open("opengauss", connStr)
if err != nil {
panic(err)
}
db := ogx.NewDB(opengaussdb, ogdialect.New())
defer db.Close()
db.AddQueryHook(ogxdebug.NewQueryHook(ogxdebug.WithVerbose(true)))
if err := createSchema(ctx, db, (*User)(nil), (*Profile)(nil)); err != nil {
panic(err)
}
defer func() {
_ = dropSchema(ctx, db, (*User)(nil), (*Profile)(nil))
}()
var users []User
if err := db.NewSelect().
Model(&users).
Column("user.*").
Relation("Profile").
Scan(ctx); 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}
}
func createSchema(ctx context.Context, db *ogx.DB, models ...interface{}) error {
for _, model := range models {
if _, err := db.NewCreateTable().Model(model).Exec(ctx); err != nil {
return err
}
}
profiles := []*Profile{
{ID: 1, Lang: "en"},
{ID: 2, Lang: "ru"},
}
if _, err := db.NewInsert().Model(&profiles).Exec(ctx); err != nil {
return err
}
users := []*User{
{ID: 1, Name: "user 1", ProfileID: 1},
{ID: 2, Name: "user 2", ProfileID: 2},
}
if _, err := db.NewInsert().Model(&users).Exec(ctx); err != nil {
return err
}
return nil
}
func dropSchema(ctx context.Context, db *ogx.DB, models ...interface{}) error {
for _, model := range models {
if _, err := db.NewDropTable().Model(model).IfExists().Cascade().Exec(ctx); err != nil {
return err
}
}
return nil
}